1 sticker costs $9.
For every 10 stickers bought, a discount of $7 is given.
- How much do 10 stickers cost?
- How much do 15 stickers cost?
- How much do 23 stickers cost?
(a)
Cost of every 10 stickers
= 10 x 9 - 7
= 90 - 7
= $83
(b)
Number of stickers that do not belong to a set
= 15 ÷ 10
= 1 r 5
Cost of the 5 extra stickers
= 5 x 9
= $45
Cost of 15 stickers
= 83 + 45
= $128
(c)
Number of sets of 10 stickers
= 23 ÷ 10
= 2 r 3
Cost of 20 stickers
= 2 x 83
= $166
Cost of 3 stickers
= 3 x 9
= $27
Cost of 23 stickers
= 166 + 27
= $193
Answer(s): (a) $83; (b) $128; (c) $193