Question

When Famke charges her phone, it gains 2 percentage points each minute. When Famke uses her phone, it loses 5 percentage points each minute.
Once, Famke used her phone for some time, and then charged it for twice the amount of time she used it. In the end, her phone lost 10 percentage points.
How long did Famke use her phone and how long did she charge it?

Answer 1

Given:

For each minute charged = + 2 percentage points

For each minute used = -5 percentage points

She charged her phone for twice as long as she used it.

In the end, she lost 10 percentage points.

To FInd:

How long was she using her phone for?

How long did she charged the phone for?

Solution

Define x:

Let the amount of time she used it be x.

The amount of time she charged her phone will be 2x

Given that she lost 10 percentage points:

2x(2) -x(5) = - 10

4x - 5x = -10

-x = -10

x = 10

Find the time she used her phone:

Amount of time she used her phone = x

Amount of time she used her phone = 10 mins

Find the amount of time she charged her phone:

Amount of time she charged her phone = 2x

Amount of time she charged her phone = 2(10)

Amount of time she charged her phone = 20 mins

Answer: She used the phone for 10 mins and charged the phone for 20 mins

Answer 2

Answer:

She used her phone for 10 mins and charged her phone for 20 mins

Step-by-step explanation:

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