At a stationery shop, staplers are sold at $8 for 1 stapler. For every 7 staplers a customer pays, an extra stapler will be given free.
- How much will Mrs Lu pay for 20 staplers?
- What is the most number of staplers Mr Chan can get for $138?
(a)
Number of staplers in one set
= 7 + 1
= 8
Cost of a set of 8 staplers
= 7 x 8
= $56
Number of sets
= 20 ÷ 8
= 2 r 4
Amount that Mrs Lu paid
= 2 x 56 + 4 x 8
= 112 + 32
= $144
(b)
Maximum number of sets
= 138 ÷ 56
= 2 r 20
Number of staplers that can be bought with remaining money
= 20 ÷ 8
= 2
Maximum number of staplers
= 8 x 2 + 2
= 18
Answer(s): (a) $144; (b) 18