At a bookstore, punchers are sold at $5 for 1 puncher. For every 7 punchers a customer pays, an extra puncher will be given free.
- How much will Mrs Oh pay for 17 punchers?
- What is the most number of punchers Mr Seah can get for $109?
(a)
Number of punchers in one set
= 7 + 1
= 8
Cost of a set of 8 punchers
= 7 x 5
= $35
Number of sets
= 17 ÷ 8
= 2 r 1
Amount that Mrs Oh paid
= 2 x 35 + 1 x 5
= 70 + 5
= $75
(b)
Maximum number of sets
= 109 ÷ 35
= 3 r 17
Number of punchers that can be bought with remaining money
= 17 ÷ 5
= 3
Maximum number of punchers
= 8 x 3 + 3
= 27
Answer(s): (a) $75; (b) 27