At a stationery shop, files are sold at $7 for 1 file. For every 5 files a customer pays, an extra file will be given free.
- How much will Mrs Fong pay for 17 files?
- What is the most number of files Mr Ng can get for $80?
(a)
Number of files in one set
= 5 + 1
= 6
Cost of a set of 6 files
= 5 x 7
= $35
Number of sets
= 17 ÷ 6
= 2 r 5
Amount that Mrs Fong paid
= 2 x 35 + 5 x 7
= 70 + 35
= $105
(b)
Maximum number of sets
= 80 ÷ 35
= 2 r 17
Number of files that can be bought with remaining money
= 17 ÷ 7
= 2
Maximum number of files
= 6 x 2 + 2
= 14
Answer(s): (a) $105; (b) 14