At a stationery kiosk, rulers are sold at $7 for 1 ruler. For every 6 rulers a customer pays, an extra ruler will be given free.
- How much will Mrs Sim pay for 12 rulers?
- What is the most number of rulers Mr Seah can get for $138?
(a)
Number of rulers in one set
= 6 + 1
= 7
Cost of a set of 7 rulers
= 6 x 7
= $42
Number of sets
= 12 ÷ 7
= 1 r 5
Amount that Mrs Sim paid
= 1 x 42 + 5 x 7
= 42 + 35
= $77
(b)
Maximum number of sets
= 138 ÷ 42
= 3 r 12
Number of rulers that can be bought with remaining money
= 12 ÷ 7
= 3
Maximum number of rulers
= 7 x 3 + 3
= 24
Answer(s): (a) $77; (b) 24