Adam pays $38 for 4 stickers and 3 marbles.
10 stickers cost as much as 2 marbles.
- How much is 1 sticker?
- How much is 1 marble?
- How much is 3 marbles and 2 stickers?
(a)
Choose the smaller group to be 1 u.
Cost of 10 stickers = Cost of 2 marbles
Cost of 5 stickers = Cost of 1 marble
Cost of 1 sticker = 1 u
Cost of 1 marble = 5 u
Cost of 4 stickers
= 4 x 1 u
= 4 u
Cost of 3 marbles
= 3 x 5 u
= 15 u
Total cost of 4 stickers and 3 marbles
= 4 u + 15 u
= 19 u
19 u = 38
1 u = 38 ÷ 19 = 2
Cost of 1 sticker = 1 u = $2
(b)
Cost of 1 marble
= 5 u
= 5 x 2
= $10
(c)
Cost of 3 marbles and 2 stickers
= 3 x 5 u + 2 x 1 u
= 15 u + 2 u
= 17 u
= 17 x 2
= $34
Answer(s): (a) $2; (b) $10; (c) $34