Answer:
E=$19.307
Step-by-step explanation:
Total number of cards = 52
If you win then you will get $50
If you lose then you will give him $20
Therefore the probability
[tex]P(first\ card\ is\ face\ card)=\dfrac{12}{52}[/tex]
[tex]P(Second\ card\ is\ face\ card)=\dfrac{11}{51}[/tex]
[tex]P(Third\ card\ is\ face\ card)=\dfrac{10}{50}[/tex]
Thus the probability for all the three cards are face card
[tex]P=\dfrac{12}{52}\times \dfrac{11}{51}\times \dfrac{10}{50}[/tex]
P=0.0099
Thus the probability for all the three cards are not face card
P=1-0.0099=0.9901
P=0.9901
Therefore , expected value
[tex]E=20\times 0.9901-50\times 0.0099[/tex]
E=$19.307
Therefore the answer will be $19.307.
the pairs of figures is similar.find x.round to the nearest tenth if necessary.from gradpoint plss help me if you have the diagram please solve for me
Answer:
4.1 feet
Step-by-step explanation:
Two shapes are said to be similar if they have the same shape and their sides are in the same proportion, i.e. the ratio of their sides are equal.
Given the two figures attached, the height of the first figure is 11 ft, while its width is 8 ft. For the second figure, its height is x feet and its length is 3 ft. Since the two figure are similar therefore the ratio of their sides are equal. Therefore:
[tex]\frac{x}{11} =\frac{3}{8}\\ \\x=\frac{3*11}{8}=4.125\\ \\x=4.1\ feet(to\ nearest\ tenth)[/tex]
Sally has 20 coins in her piggy bank, all dimes and quarters. The total amount of money is $3.05 If d = the number of dimes and q = the number of quarters Sally has, one of the linear equations that could be used to model this situations is
Answer:
[tex]d + q = 20[/tex]
[tex]0.25d + 0.10q = 3.05[/tex]
Step-by-step explanation:
Given
Coins = 20
Value = $3.05
Required
Determine the equation that represent this
From the question, we have that
d = the number of dimes
q = the number of quarters
This implies that;
[tex]d + q = 20[/tex]
Also;
[tex]1 d=\$0.25\ \ and\ \\1 q= \$0.10[/tex]---------- Standard unit of conversion;
This implies that
[tex]0.25d + 0.10q = 3.05[/tex]
Hence, the equations are:
[tex]d + q = 20[/tex]
[tex]0.25d + 0.10q = 3.05[/tex]
The coefficient of x^ky^n-k in the expansion of (x+y)^n equals (nk). True or false.
Answer:
The correct option is;
False
Step-by-step explanation:
The coefficient of x^k·y^(n-k) is nk, False
The kth coefficient of the binomial expansion, (x + y)ⁿ is [tex]\dbinom{n}{k} = \dfrac{n!}{k!\cdot (n-k)!} = C(n,k)[/tex]
Where;
k = r - 1
r = The term in the series
For an example the expansion of (x + y)⁵, we have;
(x + y)⁵ = x⁵ + 5·x⁴·y + 10·x³·y² + 10·x²·y³ + 5·x·y⁴ + y⁵
The third term, (k = 3) coefficient is 10 while n×k = 3×5 = 15
Therefore, the coefficient of x^k·y^(n-k) for the expansion (x + y)ⁿ = [tex]C(n,k)[/tex] not nk
Answer:
True
Step-by-step explanation:
apec
A bookcase has 3 shelves with a total of 24 books. The top shelf has 8 mystery books. The middle shelf has 10 math books. The bottom shelf has 6 science books. Two books are now taken off each shelf. What fraction of the books remaining on the three shelves are math books? Express your answer as a common fraction.
Answer:
4/9
Step-by-step explanation:
So, the ratio of the books is 8:10:6. After 2 books were taken off of each shelf, it became 6:8:4. All of these numbers added up is 18. So that means 8/18 of the books are math books, which can be simplified to 4/9.
Answer:
4/9
Step-by-step explanation:
There were some pieces of candy in a bowl. Shirley took half of them. Then Rose took half of the pieces left in the bowl. After that, Susan took half of the remaining pieces of candy. In the end there were 8 pieces of candy left in the bowl. How many candies were there in the bowl at the beginning?
Answer:
Number of pieces of candy in the bowl=64
Step-by-step explanation:
Let
x=number of pieces of candy in a bowl
Shirley took=1/2 of x
=1/2x
Remaining
x-1/2x
= 2x-x/2
=1/2x
Rose took half of the pieces left in the bowl=1/2 of 1/2x
=1/2*1/2x
=1/4x
Remaining
1/2x-1/4x
=2x-x/4
=1/4x
Susan took 1/2 of the remaining pieces of candy=1/2 of 1/4x
=1/2*1/4x
=1/8x
Remaining 8
1/8x=8
x=8÷1/8
=8*8/1
=64
x=64
Someone pls help if you want more points just go to my other questions and answer them pls
Answer:
I would say the answer is C.
What number :Increased by 130% is 69 i rlly need help!!!
Answer:
53.076923
Step-by-step explanation:
130% as a decimal is 1.3
Divide 69 by 1.3:
69 /1.3 = 53.076923
Answer:
30
Step-by-step explanation:
The unknown number is x.
Start with x.
To increase x by 130%, you need to add 130%of x to x.
x + 130% of x
The sum equals 69.
x + 130% of x = 69
x + 130% * x = 69
1x + 1.3x = 69
2.3x = 69
x = 30
Answer: The number is 30.
Determine what type of model best fits the given situation: An Internet phone company presently provides service to 5,000 customers at a monthly rate of $20 per month. After a market survey, it was determined that for each $1 decrease in the monthly rate an increase of 500 new customers would result. A. linear B. quadratic C. none of these D. exponential
Answer:
The best fit is A. Linear model
Step-by-step explanation:
Given:
Monthly Rate = $20, Number of customers = 5000
If there is a decrease of $1 in the monthly rate, the number of customers increase by 500.
To find:
The type of model that best fits the given situation?
Solution:
Monthly Rate = $20, Number of customers = 5000
Let us decrease the monthly rate by $1.
Monthly Rate = $20 - $1 = $19, Number of customers = 5000 + 500 = 5500
Let us decrease the monthly rate by $1 more.
Monthly Rate = $19 - $1 = $18, Number of customers = 5500 + 500 = 6000
Here, we can see that there is a linear change in the number of customers whenever there is decrease in the monthly rate.
We have 2 pair of values here,
x = 20, y = 5000
x = 19, y = 5500
Let us write the equation in slope intercept form:
[tex]y =mx+c[/tex]
Slope of a function:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
[tex]m=\dfrac{5500-5000}{19-20}\\\Rightarrow -500[/tex]
So, the equation is:
[tex]y =-500x+c[/tex]
Putting x = 20, y = 5000:
[tex]5000 =-500\times 20+c\\\Rightarrow c = 5000 +10000 = 15000[/tex]
[tex]\Rightarrow \bold{y =-500x+15000}[/tex]
Let us check whether (18, 6000) satisfies it.
Putting x = 18:
[tex]-500 \times 18 +15000 = -9000+15000 = 6000[/tex] so, it is true.
So, the answer is:
The best fit is A. Linear model
What can each term of the equation be multiplied by to eliminate the fractions before solving? x – + 2x = StartFraction one-half EndFraction x minus StartFraction 5 Over 4 EndFraction plus 2 x equals StartFraction 5 Over 6 EndFraction plus x. + x 2 6 10 12
Answer: while solving an equation involving fractions we eliminate the fraction by multiplying the LCD of all the denominators present in the equation . LCD means Least common Denominator so for this question when we try to eliminate the denominator we first try to find the LCM (2,4,6) because that will give us the LCD.
2=2
4=2·2
6=2·3
LCM = 2·2·3
LCM = 12
It means we need to multiply the 12 to each term of equation to eliminate the fractions before solving.
12
To eliminate the fractions, multiply the equation by the 12
Equation
A equation is an expression that shows the relationship between two or more variables and numbers.
Given the equation:
[tex]x-\frac{5}{4}+2x=\frac{5}{6}+x[/tex]
To eliminate the fractions, multiply by the L.C.M of the denominator of the fraction i.e. 12 to get:
12x - 15 + 24x = 10 + 12x
Find out more on Equation at: https://brainly.com/question/2972832
76.
175/50
[tex] \frac{ \sqrt[3]{175} }{ \sqrt[3]{50} } [/tex]
Answer:
Step-by-step explanation:
Factorize 175 and 50
175 = 5 * 5 * 7
50 = 5 * 5 * 2
[tex]\frac{\sqrt[3]{175}}{\sqrt[3]{}50}=\sqrt[3]{\frac{175}{50}}\\\\\\ =\sqrt[3]{\frac{5*5*7}{5*5*2}}\\\\\\=\sqrt[3]{\frac{7}{2}}[/tex]
Most evenings after dinner Duarte spends 30 minutes playing chess with his dad. Write an equation for the number of minutes, m, that Duarte spent playing chess with his dad if they played chess together (e) evenings.
Answer:
m=30e
Step-by-step explanation:
30 minutes for each evening, 2 evenings, 60 minutes
Hope this helped!
The most suitable equation that would express the time Duarte spends to play chess with his dad is m= 30e
How to use equation for expressionsNumber of minutes each evening= 30 mins=m
They played together every evening= e.
Therefore, the equation that would express the time Duarte spends to play chess with his dad is m = 30e.
Learn more about equation here:
https://brainly.com/question/2972832
#SPJ2
An exterior angle of a triangle is equal to the sum of________ opposite angle
Answer:
An exterior angle of a triangle is equal to the sum of the opposite interior angles.
Answer:
Two remote interior angles.
Rewrite the equation of the circle (x + 2)^2 + (y + 5)^2 = 9 in general form.
Answer:
x² + 4x + y² + 10y + 20 = 0
Step-by-step explanation:
Step 1: Expand (x + 2)²
x² + 2x + 2x + 4 + (y + 5)² = 9
Step 2: Combine like terms
x² + 4x + 4 + (y + 5)² = 9
Step 3: Expand (y + 5)²
x² + 4x + 4 + y² + 5y + 5y + 25 = 9
Step 4: Combine like terms
x² + 4x + 4 + y² + 10y + 25 = 9
Step 5: Move 9 over
x² + 4x + 4 + y² + 10y + 25 - 9 = 0
Step 6: Combine like terms
x² + 4x + y² + 10y + 20 = 0
Answer:
x^2+y^2+4x+10y+20=0
Step-by-step explanation:
(x+2)^2+(y+5)^2=9
x^2+4x+4+y^2+10y+25-9=0
general form: x^2+y^2+4x+10y+20=0
A particle moves along a straight line. The distance of the particle from the origin at time t is modeled by the equation below. s(t)equals2 sine t plus 3 cosine t Find a value of t between 0 and StartFraction pi Over 2 EndFraction that satisfies the equation s(t)equalsStartFraction 2 plus 3 StartRoot 3 EndRoot Over 2 EndFraction .
Answer:
The value of t that will satisfy the equation is π/6 (which is 30 degrees)
Step-by-step explanation:
The function that models the movement of the particle is given as;
S(t) = 2 sin(t) + 3 cos (t)
Now we want to the value of t between 0 and pi/2 that satisfies the equation;
s(t) = (2+ 3√3)/2 = 1 + 3√3/2
What we do here is simply find that value of t that would ensure that;
2sin(t) + 3cos(t) = 1 + 3√3/2
Without any need for rigorous calculations, this value of t can be gotten by inspection.
From our regular trigonometry, we know that the sin of angle 30 is 1/2 and its cos value is √3/2
We can make a substitution for it in this equation.
We obtain the following;
2 sin(30) + 3cos (30) and that is exactly equal to 1 + 3√3/2
Do not forget however that we have a range. And the range in question is between 0 and π/2
Kindly that π/2 in degrees is 90 degrees
So our range of values here is between 0 and 90 degrees.
So to follow the notation in the question, the value within the range that will satisfy the equation is π/6
As mountain climbers know, the higher you go, the cooler the temperature gets. At noon on July 4th last summer, the temperature at the top of Mt. Washington — elevation 6288 feet — was 56◦F. The temperature at base camp in Pinkham Notch — elevation 2041 feet — was 87◦F. It was a clear, still day. At that moment, a group of hikers reached Tuckerman Junction — elevation 5376 feet. To the nearest degree, calculate the temperature the hikers were experiencing at that time and place. When you decided how to model this situation, what assumptions did you make?
Answer:
a. 63 °F
b. When i decided to model the situation, I assumed that the temperature varied inversely as the elevation and that the change in elevation or temperature was linear.
Step-by-step explanation:
a. To model this situation, we assume the temperature varies inversely as elevation decreases since at elevation 6288 ft the temperature is 56 °F and at elevation 2041 ft, the temperature is 87 °F
So, we model this as a straight line.
Let m be the gradient of the line.
Let the (6288 ft, 56 F) represent a point on the line and (2041 ft, 87 °F) represent another point on the line.
So m = (6288 ft - 2041 ft)/(56 °F - 87 °F) = 4247 ft/-31 °F = -137 ft/°F
At elevation 5376 ft, let the temperature be T and (5376 ft, T) represent another point on the line.
Since it is a straight line, any of the other two points matched with this point should also give our gradient. Since in the gradient, we took the point (6288 ft, 56 °F) first, we will also take it first in this instant.
So m = -137 ft/ °F = (6288 ft - 5376 ft)/(56 °F - T)
-137 ft/°F = 912 ft/(56 °F - T)
(56 °F - T)/912 ft = -1/(137 ft/ °F)
56 °F - T = -912 ft/(137 ft/°F)
56 °F - T = 6.66 °F
T = 56 °F + 6.66 °F
T = 62.66 °F
T ≅ 62.7 °F
T ≅ 63 °F to the nearest degree
b. When i decided to model the situation, I assumed that the temperature varied inversely as the elevation and that the change in elevation or temperature was linear.
Use the distributive property to remove the parentheses -5(2x-3w-6)
Answer:
15w - 10x + 30.
Step-by-step explanation:
-5(2x - 3w - 6)
= (-5 * 2x) + (-5 * -3w) + (-5 * -6)
= -10x + 15w + 30
= 15w - 10x + 30.
Hope this helps!
Answer:
[tex] - 10x + 15w + 30[/tex]Step-by-step explanation:
[tex] - 5(2x - 3w - 6)[/tex]
Multiply each term in the parentheses by -5
[tex] - 5 \times 2x - 5 \times ( - 3w) - 5 \times ( - 6)[/tex]
Calculate the product
[tex] - 10x - 5 \times ( - 3x) - 5 \times ( - 6)[/tex]
Multiplying two negatives equals a positive [tex]( - ) \times ( - ) = ( + )[/tex]
[tex] - 10x + 5 \times 3w - 5 \times ( - 6)[/tex]
Calculate the product
[tex] - 10x + 15w - 5 \times ( - 6)[/tex]
Multiply the numbers
[tex] - 10x + 15w + 30[/tex]
Hope this helps..
Best regards!!
Write a rule for the linear function in the table.
f(x) = 4x + 3
f(x) = -4x - 3
1
f(x) = x + 3
Answer:
I guess that you want to know the transformations:
We start with:
f(x) = y = 4*x + 3
a)the transformed function is:
f(x) = y = -4*x - 3
So the sign changed.
This means that we go from (x, y) to (x, - y)
This is a reflection over the x-axis which changes the sin of the y component.
b) Now we go to f(x) = 4*x + 3
So the coefficient in the leading term changed.
This is a horizontal contraction:
A horizontal contraction of factor K for the function g(x) is: g(K*x)
In our case, we have:
f(K*x) = 4*(k*x) + 3 = x + 3
4*k*x = x
4*k = 1
k = 1/4
Then the transformation is an horizontal contraction of scale factor 1/4.
Give the excluded values for 6/t+5 + 2/t-5 = 3t-1/t^2-25. Do not solve
A)25
B)-5,5
C)5,25
D)-5,5,25
Please help i don’t understand
Answer:
B -5, and 5
Step-by-step explanation:
you can't have zero on the bottom
What is the effect on the graph of f(x) if it is changed to f(x) + 2 and f(x + 2)?
Answer:
For f(x)+2, it goes along the y axis, 2 units.
For f(x+2), it goes along the x axis, -2 untis.
Step-by-step explanation:
Use multiplication to solve the proportion
7/16 = x/4
Answer:
7/16=x/4
4 times 7/16= 4 times x/4
7/4=x
Step-by-step explanation:
Answer:
1.75Step-by-step explanation:
[tex] \frac{7}{16} = \frac{x}{4} [/tex]
Apply cross product property
[tex]16 x = 7 \times 4[/tex]
Multiply the numbers
[tex]16x = 28[/tex]
Divide both sides of the equation by 16
[tex] \frac{16x}{16} = \frac{28}{16} [/tex]
Calculate
[tex]x = 1.75[/tex]
Hope this helps...
Best regards!!
11.1/0.01= what is the answer
Answer:
1,110
Step-by-step explanation:
calculator
Last season, a softball team played 18 games. The team won 15 of these games. What is the ratio of the softball team's wins to its total number of games played ?
Answer:
5:6Step-by-step explanation:
Given the total number of games played by the softball team = 18 games
Total games won = 15 games
Ratio of the softball team's wins to its total number of games played can be gotten by simply dividing the total games won by the total games played
Ratio = [tex]\frac{total \ teams's win}{total\ number\ of \ games\ played}[/tex]
[tex]Ratio = \frac{15}{18}[/tex]
Expressing the ratio in its lowest term
[tex]Ratio = \frac{3*5}{3*6} \\\\Ratio = \frac{5}{6}[/tex]
Hence, the ratio of the softball team's wins to its total number of games played is 5:6
Marci has taken out a loan of $5,000 for a term of 24 months (2 years) at an interest rate of 8.5%. Use the amortization table provided to
complete the statement.
Monthly Payment per $1,000 of Principal
Rate | 1 Year 2 Years 3 Years 4 Years 5 Years
6.5% $86.30 $44.55 $59.35 $23.71 $19.57
7.0% $86.53 $44.77 $31.88 $23.95 $19.80
7.5% $86.76 $45.00 $51.71 $24.18 $20.04
8.0% $86.99 $45.23 $31.34 $24.41 $20.28
8.5% $87.22 $45.46 $24.65 $24.65 $20.52
9.0% $87.45 $45.68 $31.80 $24.89 $20.76
Marci's monthly payment will be $
and her total finance charge over the course of the loan will be $
Answer:
$227.30$455.20Step-by-step explanation:
The table tells you that Marci's monthly payment on a 2-year loan at 8.5% will be $45.46 on each $1000 borrowed. For her $5000 loan, her monthly payment will be 5 times the table value, or ...
monthly payment = $5000/$1000 × $45.46
monthly payment = $227.30
__
Her total of 24 payments will be ...
total repaid = 24 × $227.30 = $5,445.20
That amount is $445.20 more than the amount borrowed, so that is Marci's finance charge.
__
Marci's monthly payment will be $227.30, and her total finance charge will be $455.20.
A bus traveled 40 miles during the second hour of a trip. This was 1/3 more than the distance traveled during the first hour. In the third hour the bus traveled a distance that was 1/4 more than in the second hour. What was the total distance that the bus traveled in 3 hours
Answer:
120 miles
Step-by-step explanation:
Distance in 2nd hour: 40 miles
Distance in 1st hour:
40/(4/3) = 30 miles
Distance in 3rd hour:
(5/4) * 40 = 50 miles
Total distance:
40 + 30 + 50 = 120 miles
25 POINTS + BRAINLIEST !!!! A fruit bowl contains apples and bananas in the ration 4 : 5. Two apples are removed changing the ratio to 2 : 3. Work out the total number of fruit that remain in the bowl.
Answer:
Total number of fruits remaining = 25
Step-by-step explanation:
Let the number of
apples = 4x
bananas = 5x
Therefore
4x-2 / 5x = 2 / 3
Solve for x, cross multiply
3(4x-2) = 2(5x)
12x - 6 = 10 x
2x = 6
x = 3
Apples = 4*3 = 12
Bananas = 5*3 = 15
Apples remaining = 12-2 = 10
Total number of fruits remaining = 10+15 = 25
Answer:
[tex]\boxed{25 \ fruits}[/tex]
Step-by-step explanation:
Let apples be 4x and Bananas be 5x
So, the given condition is:
[tex]\frac{4x-2}{5x} = \frac{2}{3}[/tex]
Cross Multiplying
5x*2 = 3(4x-2)
10x = 12x - 6
Adding 6 to both sides
10x+6 = 12x
12x - 10x = 6
2x = 6
x = 3
Now, Fruits remaining in the bowl are:
=> 4x-2 + 5x
=> 12 - 2 + 15
=> 10+15
=> 25
Represent the expression
(4 x 1,000) + (3 x 100) + (6 x
1/100) + (7x1000)
as a decimal number.
Answer:
The answer is 11 300.06
[tex](4 \times 1000) + (3 \times 100) + (6 \times \frac{1}{100}) + (7 \times 1000) [/tex]
[tex] = 4000 + 300 + \frac{6}{100} + 7000[/tex]
[tex] = 11 \: 300 + 0.06[/tex]
[tex] = 11 \: 300.06[/tex]
Of his take-home pay each month, Jerry spends 1/6 on car payment and 1/4 on food. What fraction of his take-home pay is left after paying for these two items?
Answer:
The fraction of Jerry's take-home pay that is left after paying for these two items is 7/12.
Step-by-step explanation:
Consider that the total take-home pay each month Jerry receives is, $x.
It is provided that:
Jerry spends 1/6 on car payment, i.e. Car Payment = [tex]\frac{1}{6}x[/tex].Jerry spends 1/4 on food, i.e. Food = [tex]\frac{1}{4}x[/tex].The remaining amount can be computed by subtracting the amount spent from the total amount.
Compute the amount Jerry has spent so far:
Amount Spent = Car Payment + Food
[tex]=\frac{1}{6}x+\frac{1}{4}x\\\\=[\frac{1}{6}+\frac{1}{4}]x\\\\=[\frac{2+3}{12}]x\\\\=\frac{5}{12}x[/tex]
Compute the remaining amount as follows:
Remaining Amount = Total Amount - Amount Spent
[tex]=x-\frac{5}{12}x\\\\=[1-\frac{5}{12}]x\\\\=[\frac{12-5}{12}]x\\\\=\frac{7}{12}x[/tex]
Thus, the fraction of Jerry's take-home pay that is left after paying for these two items is 7/12.
how to do this question plz
Answer:
148 cm ^2
Step-by-step explanation:
Hey there!
Well is the area of the base is 30 then we can conclude that the side lengths are 5 and 6.
Then if the volume is 120 we can do,
120 ÷ 30 = 4
So the height is 4 cm.
Now we already have the area of the base we just need to find the area of the rest of the rectangles.
If the bottom base is 30 then the top base is also 30.
30 + 30 = 60cm^2
Now we can do the two rectangles on the side that have side lengths of 5 and 4.
5*4 = 20
20+20 = 40 cm^2
Now we can do the two final rectangles that have side lengths of 6 and 4.
6*4=24
24 + 24 = 48 cm^2
Now we can add all the areas up,
48 + 40 + 60
= 148 cm^2
Hope this helps :)
John wants to nail a thumbtack on his circular board, pictured below. If the thumbtack is equally likely to be placed anywhere on the board, what is the probability that the thumbtack will be placed on the inner circle? Use 3.14 for , and round your answer to the nearest whole percent. A. 51% B. 55% C. 57% D. 60%
Answer:
[tex]Probability = 51\%[/tex]
Step-by-step explanation:
Given
Radius of inner circle = 5ft
Radius of outer circle = 7ft
Required
Determine the probability that the thumbtack will be placed on the inner circle
We start by calculating the area of both circles;
Inner Circle
[tex]Area = \pi r^2[/tex]
[tex]Area = 3.14 * 5^2[/tex]
[tex]Area = 3.14 * 25[/tex]
[tex]Area = 78.5[/tex]
Outer Circle
[tex]Area = \pi R^2[/tex]
[tex]Area = 3.14 * 7^2[/tex]
[tex]Area = 3.14 * 49[/tex]
[tex]Area = 153.86[/tex]
At this point, the probability can be calculated;
The probability = Area of Inner Circle / Area of Outer Circle
[tex]Probability = \frac{78.5}{153.86}[/tex]
[tex]Probability = 0.51020408163[/tex]
Convert to percentage
[tex]Probability = 0.51020408163 * 100\%[/tex]
[tex]Probability = 51.020408163\%[/tex]
Approximate
[tex]Probability = 51\%[/tex]
help plz its math and i will give brainlest if u answer
Answer:
not a right triangle
Step-by-step explanation:
We can use the Pythagorean theorem to see if it is a right triangle
a^2 + b^2 = c^2
15^2 + 12^2 = 21^2
225 + 144 = 441
369 = 441
This is not true so it is not a right triangle
Answer:
Step-by-step explanation:
A triangle is a right angled triangle if sum of squares of two sides is equal to the square of third side.
12²+15²=144+225=369
21²=441
so a²+b²≠c²
it is not a right angled triangle.