Word Problem

Question

When making a long distance call from a certain pay phone, the first three minutes of a call cost $2.15. After that, each additional minute or portion of a minute of that call costs $0.40. Find the maximum number of minutes one can call long distance for $9.75.

How do i solve this problem step by step?

Answer 1

9.75 = 0.40* (N-3) + 2.15 where N is the number of minutes;  3 minutes is guaranteed by virtue of $9.75

 

975 = 40(N-3) + 215 <--- expresses the amount in pennies by multiplying everything by 100 to clear away the decimals

 

975 = 40N - 120 + 215

 

975 = 40N + 95

 

880 = 40N

 

N = 880/40 = 22

 

22 minutes