Adam earns $2 for every car he washes.
He gets $3 bonus for every 5 cars he washes.

1. How much will Adam earn if he washes every 5 cars?   
2. If Adam wants to earn $17, how many cars must he wash? 
3. If Adam wants to earn $39, how many cars must he wash? 
4. If Adam wants to earn $45, how many cars must he wash? 

(a)
Amount that Adam will earn for washing every 5 cars
= 2 x 5 + 3
= $13

(b)
Number of sets of $13
= 17 ÷ 13
= 1 r 4

Number of cars in 1 set
= 1 x 5
= 5

Number of extra cars that he has to wash
= 4 ÷ 2
= 2

Total number of cars that Adam must wash
= 5 + 2
= 7

(c)
Number of sets of $13
= 39 ÷ 13
= 3 (Note that there is no remainder.)

Total number of cars that Adam must wash
= 3 x 5
= 15

(d)
If Adam wants to earn $45, how many cars must he wash?

Number of sets of $45
= 45 ÷ 13
= 3 r 6

Number of cars in 5 sets
= 3 x 5
= 15

Number of extra cars that he has to wash
= 6 ÷ 2
= 3

Total number of cars
= 15 + 3
= 18

Answer(s): (a) $13; (b) 7; (c) 15; (d) 18