At a book shop, folders are sold at $7 for 1 folder. For every 6 folders a customer pays, an extra folder will be given free.
- How much will Mrs Sim pay for 17 folders?
- What is the most number of folders Mr Song can get for $133?
(a)
Number of folders in one set
= 6 + 1
= 7
Cost of a set of 7 folders
= 6 x 7
= $42
Number of sets
= 17 ÷ 7
= 2 r 3
Amount that Mrs Sim paid
= 2 x 42 + 3 x 7
= 84 + 21
= $105
(b)
Maximum number of sets
= 133 ÷ 42
= 3 r 17
Number of folders that can be bought with remaining money
= 17 ÷ 7
= 3
Maximum number of folders
= 7 x 3 + 3
= 24
Answer(s): (a) $105; (b) 24