Adam pays $30 for 3 stickers and 5 marbles.
3 stickers cost as much as 5 marbles.
- How much is 1 sticker?
- How much is 1 marble?
- How much is 4 marbles and 3 stickers?
(a)
LCM of 3 and 5 = 15
Cost of 3 stickers = 15 u
Cost of 1 sticker = 15 u ÷ 3 = 5 u
Cost of 5 marbles = 15 u
Cost of 1 marble = 15 u ÷ 5 = 3 u
Cost of 3 stickers = 3 x 5 u = 15 u
Cost of 5 marbles = 5 x 3 u = 15 u
Total cost of 3 stickers and 5 marbles
= 15 u + 15 u
= 30 u
30 u = 30
1 u = 30 ÷ 30 = 1
Cost of 1 sticker
= 5 u
= 5 x 1
= $5
(b)
Cost of 1 marble
= 3 u
= 3 x 1
= $3
(c)
Cost of 4 marbles and 3 stickers
= 4 x 3 u + 3 x 5 u
= 12 u + 15 u
= 27 u
= 27 x 1
= $27
Answer(s): (a) $5; (b) $3; (c) $27