Question

A cab company calculates cab fares using the expression 1.50d + 3, where d is the distance traveled in miles. If a passenger has to pay a $21 fare for a ride, which number from the set {9, 12, 15, 18} is the value of d?

9

Answer 1

Set 1.50d + 3 equal to $21

1.50d + 3 = 21
Now solve for d
1.50d + 3 - 3 = 21 - 3
1.50d = 18
d = 12

Answer 2

1.50d + 3 = 21
1.50d = 18
d = 18/1.50
d = 12