It takes 20 minutes for John to go to the bathroom 8 times. How long would it take to go 6 times?
Let's think step by step.
15
He spends 20 / 8 = 2.

5 minutes each time he goes in.

So it would take 2.

5 * 6 = 15 minutes to go 6 times.

.

The final answer: 15