1 sticker costs $7.
For every 10 stickers bought, a discount of $6 is given.
- How much do 10 stickers cost?
- How much do 13 stickers cost?
- How much do 39 stickers cost?
(a)
Cost of every 10 stickers
= 10 x 7 - 6
= 70 - 6
= $64
(b)
Number of stickers that do not belong to a set
= 13 ÷ 10
= 1 r 3
Cost of the 3 extra stickers
= 3 x 7
= $21
Cost of 13 stickers
= 64 + 21
= $85
(c)
Number of sets of 10 stickers
= 39 ÷ 10
= 3 r 9
Cost of 30 stickers
= 3 x 64
= $192
Cost of 9 stickers
= 9 x 7
= $63
Cost of 39 stickers
= 192 + 63
= $255
Answer(s): (a) $64; (b) $85; (c) $255