Adam pays $38 for 3 stickers and 2 marbles.
5 stickers cost as much as 3 marbles.
- How much is 1 sticker?
- How much is 1 marble?
- How much is 4 marbles and 5 stickers?
(a)
LCM of 5 and 3 = 15
Cost of 5 stickers = 15 u
Cost of 1 sticker = 15 u ÷ 5 = 3 u
Cost of 3 marbles = 15 u
Cost of 1 marble = 15 u ÷ 3 = 5 u
Cost of 3 stickers = 3 x 3 u = 9 u
Cost of 2 marbles = 2 x 5 u = 10 u
Total cost of 3 stickers and 2 marbles
= 9 u + 10 u
= 19 u
19 u = 38
1 u = 38 ÷ 19 = 2
Cost of 1 sticker
= 3 u
= 3 x 2
= $6
(b)
Cost of 1 marble
= 5 u
= 5 x 2
= $10
(c)
Cost of 4 marbles and 5 stickers
= 4 x 5 u + 5 x 3 u
= 20 u + 15 u
= 35 u
= 35 x 2
= $70
Answer(s): (a) $6; (b) $10; (c) $70
