Adam pays $17 for 5 stickers and 4 marbles.
9 stickers cost as much as 3 marbles.
- How much is 1 sticker?
- How much is 1 marble?
- How much is 5 marbles and 3 stickers?
(a)
Choose the smaller group to be 1 u.
Cost of 9 stickers = Cost of 3 marbles
Cost of 3 stickers = Cost of 1 marble
Cost of 1 sticker = 1 u
Cost of 1 marble = 3 u
Cost of 5 stickers
= 5 x 1 u
= 5 u
Cost of 4 marbles
= 4 x 3 u
= 12 u
Total cost of 5 stickers and 4 marbles
= 5 u + 12 u
= 17 u
17 u = 17
1 u = 17 ÷ 17 = 1
Cost of 1 sticker = 1 u = $1
(b)
Cost of 1 marble
= 3 u
= 3 x 1
= $3
(c)
Cost of 5 marbles and 3 stickers
= 5 x 3 u + 3 x 1 u
= 15 u + 3 u
= 18 u
= 18 x 1
= $18
Answer(s): (a) $1; (b) $3; (c) $18