1 sticker costs $4.
For every 10 stickers bought, a discount of $3 is given.
- How much do 10 stickers cost?
- How much do 17 stickers cost?
- How much do 39 stickers cost?
(a)
Cost of every 10 stickers
= 10 x 4 - 3
= 40 - 3
= $37
(b)
Number of stickers that do not belong to a set
= 17 ÷ 10
= 1 r 7
Cost of the 7 extra stickers
= 7 x 4
= $28
Cost of 17 stickers
= 37 + 28
= $65
(c)
Number of sets of 10 stickers
= 39 ÷ 10
= 3 r 9
Cost of 30 stickers
= 3 x 37
= $111
Cost of 9 stickers
= 9 x 4
= $36
Cost of 39 stickers
= 111 + 36
= $147
Answer(s): (a) $37; (b) $65; (c) $147