Question

A cell phone battery charges at a rate of 16% every thirty minutes. When initially plugged into the charger, a cell phone has 10% battery.
1.Write an equation relating the amount of time, measured in hours, it takes to charge a cell phone as a function of the battery charge.
2.Use complete sentences to describe the rate in which the battery charges in terms of the time that it is charging.

Answer 1

30 minutes is 1/2 an hour so 16 x 2 = 32 the phone charges at 32% per hour.

1. Multiply the number of hours by the rate and add the original 10% to that for total charge:

Y = 0.32h + 0.10

2. The phone charges at 16% every thirty minutes which is a half hour so you double the rate it charges to get the rate per hour. The phone charges at 32% per hour that it is charging.

Answer 2

30 minutes is 1/2 an hour so 16 x 2 = 32 the phone charges at 32% per hour.

1. Multiply the number of hours by the rate and add the original 10% to that for total charge:

Y = 0.32h + 0.10

2. The phone charges at 16% every thirty minutes which is a half hour so you double the rate it charges to get the rate per hour. The phone charges at 32% per hour that it is charging.