Answer:
Unit rate is a rate that has 1 as denominator.
Given the rate: 6 inches / 12 hours, we have to divide numerator and denominator by 12 to transform the denominator in 1, as follows:
\frac{6}{12} = \frac{6/12}{12/12} =
12
6
=
12/12
6/12
= 0.5 inches/hour