Answer:
3.6 hours
Step-by-step explanation:
The computation of the number of hours will the battery last is given below:
Given that
The capacity of her battery is 2 by 5
And, it declines 1 by 9 for every hour
So,
[tex]= \frac{2}{5}\times \frac{9}{1}\\\\= \frac{18}{5}\\\\= 3\frac{3}{5}[/tex]
= 3.6 hours