We are given that Vera's battery life is down to = [tex]\frac{2}{5}[/tex].
Rate of it drain = [tex]\frac{1}{9}[/tex] per our.
In order to find the number of hours will her battery last, we need to divide [tex]\frac{2}{5}[/tex] by [tex]\frac{1}{9}[/tex].
[tex]\frac{2}{5}[/tex] ÷[tex]\frac{1}{9}[/tex]
Let us convert division sign in multiplication and flip the second fraction, we get
[tex]\frac{2}{5} \times \frac{9}{1}[/tex]
= [tex]\frac{18}{5}[/tex]
= 3.6
Therefore, her battery will last in 3.6 hours.
