Adam pays $1.60 for a marble and a sticker.
The marble costs 7 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 = 7 u
Total cost of a sticker and a marble
= 1 u + 7 u
= 8 u
8 u = 1.60
1 u = 1.60 ÷ 8 = 0.20
Cost of the marble
= 7 u
= 7 x 0.20
= $1.40
(b)
Cost of 2 stickers and 3 marbles
= 2 x 1 u + 3 x 7 u
= 2 u + 21 u
= 23 u
= 23 x 0.20
= $4.60
Answer(s): (a) $1.40; (b) $4.60