A phone company charges $0.50 per minute during the day and $0.10 per
minute at night. How many daytime and night time minutes could you use in a
week if you wanted to pay less than $20? Write an inequality to represent all
possible solutions.
0.50d + 0.10n < 20
0.60x20
0.50d + 0.10n 20
0.60x < 20