Adam earns $3 for every car he washes.
He gets $6 bonus for every 4 cars he washes.
- How much will Adam earn if he washes every 4 cars?
- If Adam wants to earn $21, how many cars must he wash?
- If Adam wants to earn $54, how many cars must he wash?
- If Adam wants to earn $63, how many cars must he wash?
(a)
Amount that Adam will earn for washing every 4 cars
= 3 x 4 + 6
= $18
(b)
Number of sets of $18
= 21 ÷ 18
= 1 r 3
Number of cars in 1 set
= 1 x 4
= 4
Number of extra cars that he has to wash
= 3 ÷ 3
= 1
Total number of cars that Adam must wash
= 4 + 1
= 5
(c)
Number of sets of $18
= 54 ÷ 18
= 3 (Note that there is no remainder.)
Total number of cars that Adam must wash
= 3 x 4
= 12
(d)
If Adam wants to earn $63, how many cars must he wash?
Number of sets of $63
= 63 ÷ 18
= 3 r 9
Number of cars in 4 sets
= 3 x 4
= 12
Number of extra cars that he has to wash
= 9 ÷ 3
= 3
Total number of cars
= 12 + 3
= 15
Answer(s): (a) $18; (b) 5; (c) 12; (d) 15