Question

A phone company charges 50 cents per minute during the daytime and 10 cents per minute at night.

How many daytime minutes and nighttime minutes could you use in one week if you wanted to pay less
than $20?

Answer 1

You could talk on the phone for 200 minutes at night, or 40 minutes during the day.

For every 5 minutes you reduced your night time talking, you could talk during the day for 1 minute.

Explanation:

0.50d + 0.10n < $20

0.50d < $20 --> d < 40 minutes

0.10n < $20 --> n < 200 minutes