A battery was charged. When the charging began, it was 23 percent full. After 30 minutes of charging, the battery was 89 percent full. how fast did the battery charge and how long did it take?

QUESTION:

A battery was charged. When the charging began, it was 23 percent full. After 30 minutes of charging, the battery was 89 percent full. how fast did the battery charge and how long did it take?

Solution :

Given

procedure

Let the rate of charging be r .

r = (change in charge level) / (time interval) = (89% - 23%) / (30 min) = 2.2 % per minute

charge = (rate of charging)(time) + (initial charge)

100% = r*t + 23%

100% = (2.2 %/min)t + 23%

Solve for t and get

t = [(100 - 23) / 2.2]

Answer = 35 min

Step-by-step explanation:

The battery was charged at a rate of 2.2 percent per minute. It took the battery 35 minutes to be fully charged.

you probably already have the answer but anyways it's b. 15.0

step-by-step explanation: