Solution:
Given that,
Bethany cut off 18 inches of her hair
It took her 3 years to grow it back
How much did her hair grow each month?
From given,
length of hair = 18 inches
Number of years = 3 years
Convert to months
1 years = 12 months
3 years = 3 x 12 = 36 months
Thus, length of hair grown in 1 month is given as:
[tex]\text{length of hair grown in 1 month } = \frac{\text{length of hair}}{\text{36 months}}\\\\\text{length of hair grown in 1 month } = \frac{18}{36}\\\\\text{length of hair grown in 1 month } = 0.5[/tex]
Thus, 0.5 inches of hair is grown each month