Adam earns $3 for every car he washes.
He gets $6 bonus for every 5 cars he washes.
- How much will Adam earn if he washes every 5 cars?
- If Adam wants to earn $30, how many cars must he wash?
- If Adam wants to earn $42, how many cars must he wash?
- If Adam wants to earn $54, how many cars must he wash?
(a)
Amount that Adam will earn for washing every 5 cars
= 3 x 5 + 6
= $21
(b)
Number of sets of $21
= 30 ÷ 21
= 1 r 9
Number of cars in 1 set
= 1 x 5
= 5
Number of extra cars that he has to wash
= 9 ÷ 3
= 3
Total number of cars that Adam must wash
= 5 + 3
= 8
(c)
Number of sets of $21
= 42 ÷ 21
= 2 (Note that there is no remainder.)
Total number of cars that Adam must wash
= 2 x 5
= 10
(d)
If Adam wants to earn $54, how many cars must he wash?
Number of sets of $54
= 54 ÷ 21
= 2 r 12
Number of cars in 5 sets
= 2 x 5
= 10
Number of extra cars that he has to wash
= 12 ÷ 3
= 4
Total number of cars
= 10 + 4
= 14
Answer(s): (a) $21; (b) 8; (c) 10; (d) 14