Adam pays $2.40 for a marble and a sticker.
The marble costs 2 times as much as the sticker.
- What is the cost of 1 marble?
- How much is the cost of 2 stickers and 3 marbles?
(a)
Cost of a sticker = 1 u
Cost of a marble = 2 u
Total cost of a sticker and a marble
= 1 u + 2 u
= 3 u
3 u = 2.40
1 u = 2.40 ÷ 3 = 0.80
Cost of the marble
= 2 u
= 2 x 0.80
= $1.60
(b)
Cost of 2 stickers and 3 marbles
= 2 x 1 u + 3 x 2 u
= 2 u + 6 u
= 8 u
= 8 x 0.80
= $6.40
Answer(s): (a) $1.60; (b) $6.40