Adam pays $3.20 for a sticker and a marble.
The sticker costs 7 times as much as the marble.
- What is the cost of 1 sticker?
- How much is the cost of 2 marbles and 3 stickers?
(a)
Cost of a marble = 1 u
Cost of a sticker = 7 u
Total cost of a marble and a sticker
= 1 u + 7 u
= 8 u
8 u = 3.20
1 u = 3.20 ÷ 8 = 0.40
Cost of the sticker
= 7 u
= 7 x 0.40
= $2.80
(b)
Cost of 2 marbles and 3 stickers
= 2 x 1 u + 3 x 7 u
= 2 u + 21 u
= 23 u
= 23 x 0.40
= $9.20
Answer(s): (a) $2.80; (b) $9.20