1 sticker costs $8.
For every 10 stickers bought, a discount of $3 is given.
- How much do 10 stickers cost?
- How much do 19 stickers cost?
- How much do 31 stickers cost?
(a)
Cost of every 10 stickers
= 10 x 8 - 3
= 80 - 3
= $77
(b)
Number of stickers that do not belong to a set
= 19 ÷ 10
= 1 r 9
Cost of the 9 extra stickers
= 9 x 8
= $72
Cost of 19 stickers
= 77 + 72
= $149
(c)
Number of sets of 10 stickers
= 31 ÷ 10
= 3 r 1
Cost of 30 stickers
= 3 x 77
= $231
Cost of 1 stickers
= 1 x 8
= $8
Cost of 31 stickers
= 231 + 8
= $239
Answer(s): (a) $77; (b) $149; (c) $239