Adam pays $18 for 3 stickers and 4 marbles.
3 stickers cost as much as 2 marbles.
- How much is 1 sticker?
- How much is 1 marble?
- How much is 5 marbles and 4 stickers?
(a)
LCM of 3 and 2 = 6
Cost of 3 stickers = 6 u
Cost of 1 sticker = 6 u ÷ 3 = 2 u
Cost of 2 marbles = 6 u
Cost of 1 marble = 6 u ÷ 2 = 3 u
Cost of 3 stickers = 3 x 2 u = 6 u
Cost of 4 marbles = 4 x 3 u = 12 u
Total cost of 3 stickers and 4 marbles
= 6 u + 12 u
= 18 u
18 u = 18
1 u = 18 ÷ 18 = 1
Cost of 1 sticker
= 2 u
= 2 x 1
= $2
(b)
Cost of 1 marble
= 3 u
= 3 x 1
= $3
(c)
Cost of 5 marbles and 4 stickers
= 5 x 3 u + 4 x 2 u
= 15 u + 8 u
= 23 u
= 23 x 1
= $23
Answer(s): (a) $2; (b) $3; (c) $23