Adam pays $3.20 for a marble and a bead.
The marble costs 7 times as much as the bead.
- What is the cost of 1 marble?
- How much is the cost of 5 beads and 3 marbles?
(a)
Cost of a bead = 1 u
Cost of a marble = 7 u
Total cost of a bead and a marble
= 1 u + 7 u
= 8 u
8 u = 3.20
1 u = 3.20 ÷ 8 = 0.40
Cost of the marble
= 7 u
= 7 x 0.40
= $2.80
(b)
Cost of 5 beads and 3 marbles
= 5 x 1 u + 3 x 7 u
= 5 u + 21 u
= 26 u
= 26 x 0.40
= $10.40
Answer(s): (a) $2.80; (b) $10.40