Answer:
1.95 hours or 1 hour and 57 minutes.
Explanation:
You can read the problem as 13% of the battery. "Of" is a keyword that means to multiply.
The battery lasts 15 hours, so multiply by 13%. You need to change 13% to a decimal first by dividing it by 100, or moving the decimal left two places.
13% = 0.13
Now solve.
0.13 × 15 = 1.95
If you need to convert the 0.95 to minutes, multiply it by 60 since there are 60 minutes in an hour.
0.95 x 60 = 57 minutes.