Question

A battery was charged. When the charging began, it was 23 2323 percent full. After 30 3030 minutes of charging, the battery was 89 8989 percent full. How fast was the battery charged? How long did it take the battery to be fully charged?

Answer 1

a. 2.2% per minute

b. 35 minutes

Explanation:

Firstly, we want to calculate the rate at which is charges

Mathematically, that would be;

(89-23)/30 = 66/30 = 2.2% per minute

Secondly. we want to know the time it took to be fully charged

That will be;

23 + 2.2(x) = 100

2.2x = 100-23

2.2x = 77

x = 77/2.2

x = 35 minutes