1 sticker costs $9.
For every 10 stickers bought, a discount of $6 is given.
- How much do 10 stickers cost?
- How much do 16 stickers cost?
- How much do 21 stickers cost?
(a)
Cost of every 10 stickers
= 10 x 9 - 6
= 90 - 6
= $84
(b)
Number of stickers that do not belong to a set
= 16 ÷ 10
= 1 r 6
Cost of the 6 extra stickers
= 6 x 9
= $54
Cost of 16 stickers
= 84 + 54
= $138
(c)
Number of sets of 10 stickers
= 21 ÷ 10
= 2 r 1
Cost of 20 stickers
= 2 x 84
= $168
Cost of 1 stickers
= 1 x 9
= $9
Cost of 21 stickers
= 168 + 9
= $177
Answer(s): (a) $84; (b) $138; (c) $177