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 was the battery charged?

_____ percent per minute
How long did it take the battery to be fully charged?

_____ minutes

Answer 1

The battery was charged at a speed of 2.2% per minute. It took 3500 minutes for the battery to be fully charged.

Step-by-step explanation:

To calculate the speed at which the battery was charged, we can subtract the initial charge from the final charge and divide it by the time taken to charge. The initial charge was 23%, which can be represented as 0.23 as a decimal, and the final charge was 89%, which can be represented as 0.89. The time taken to charge was 30 minutes.

The speed of charging can be calculated as follows: (0.89 - 0.23) / 30 = 0.66 / 30. This equals approximately 0.022, or 2.2% per minute.

To determine how long it takes for the battery to be fully charged, we can calculate the time based on the charging speed. Since the battery started at 23% and needs to reach 100%, we can subtract 23 from 100 to get the remaining charge, which is 77%. We can then divide this remaining charge by the charging speed, which is 0.022. Thus, the time taken to fully charge the battery is 77 / 0.022 = 3500 minutes.

Answer 2

Since it started at 23 percent and went to 89 percent, the increase is 66 percent.

Since it took 30 minutes to rise 66 percent, the rate is 2.2 percent per minute.

In order to find how long it will take to charge fully, subtract 23 from 100

100-23=77

77/2.2=35. It should take 35 minutes to charge from 23% to 100%