Question

Frank decided to keep track of his sleep using a fitness tracker. He was surprised to learn that there was 21 minutes of awake time during the seven hours when he was supposed to be asleep at night.

What percentage of the seven hours was Frank awake during the night?

HELP

Answer 1

5%

Explanation:

Let's first convert 7 hours to minutes:

1 hour = 60 minutes

7 hours = 60*7 minutes = 420 minutes

Now we find the percentage...

21=n%*420

21=n/100*420

21=21n/5

Multiply both sides by 5

105=21n

Divide boths sides by 21

n=5

5% of the 7 hours