Evan listens to music on his MP3 while doing his chores. When he first turns on his MP3 player, it has 3/5 of its battery life left. When Evan finishes the chores, it has 35% of its battery life left. How much time does Evan spend doing chores if his MP3 player has 2 hours of battery life when fully charged?

I think the answer is 2hrs and 14 min.

3/5 = 60/100 = 60%

so started with 60% charge
60 - 35 = 25% used doing chores
so he used 25% of 2 hour charge = 1/2 hour
By the way:
If the battery only holds enough charge for 2 hours of use, how could he use 2 hours and 15 minutes?

Never mind, I know what I did wrong. Instead of subtracting the two I added. The answer is actually 30 minutes

Maya goes to the mall to buy some shoes. The shoes that she wants usually cost $42, but they were on sale for 40% less. There is a 5% sales tax, and Maya pays for the shoes with a $50 bill. how much change does Maya resive.

To solve this problem, we need to determine how the battery life decreases over time and then calculate the amount of time it takes for the battery to decrease from 3/5 (60%) to 35% of its capacity.

First, let's calculate the difference in battery life between the initial and final states. The initial battery life is 3/5 (60%) of the total battery life, which is 2 hours. Therefore, the initial battery life is (3/5) * 2 hours = 6/5 = 1.2 hours.

The final battery life is 35% of the total battery life, which is 2 hours. Therefore, the final battery life is (35/100) * 2 hours = 0.7 hours.

Next, let's calculate the difference in battery life between the initial and final states. The decrease in battery life is 1.2 hours - 0.7 hours = 0.5 hours.

Now, to convert this time from hours to minutes, we multiply it by 60 (since there are 60 minutes in an hour): 0.5 hours * 60 minutes/hour = 30 minutes.

Therefore, Evan spends 30 minutes doing his chores if his MP3 player has 2 hours of battery life when fully charged.

So, the correct answer is 0 hours and 30 minutes, not 2 hours and 14 minutes.