1 sticker costs $3.
For every 10 stickers bought, a discount of $7 is given.
- How much do 10 stickers cost?
- How much do 17 stickers cost?
- How much do 31 stickers cost?
(a)
Cost of every 10 stickers
= 10 x 3 - 7
= 30 - 7
= $23
(b)
Number of stickers that do not belong to a set
= 17 ÷ 10
= 1 r 7
Cost of the 7 extra stickers
= 7 x 3
= $21
Cost of 17 stickers
= 23 + 21
= $44
(c)
Number of sets of 10 stickers
= 31 ÷ 10
= 3 r 1
Cost of 30 stickers
= 3 x 23
= $69
Cost of 1 stickers
= 1 x 3
= $3
Cost of 31 stickers
= 69 + 3
= $72
Answer(s): (a) $23; (b) $44; (c) $72