Adam pays $2.70 for a marble and a bead.
The marble costs 8 times as much as the bead.
- What is the cost of 1 marble?
- How much is the cost of 3 beads and 5 marbles?
(a)
Cost of a bead = 1 u
Cost of a marble = 8 u
Total cost of a bead and a marble
= 1 u + 8 u
= 9 u
9 u = 2.70
1 u = 2.70 ÷ 9 = 0.30
Cost of the marble
= 8 u
= 8 x 0.30
= $2.40
(b)
Cost of 3 beads and 5 marbles
= 3 x 1 u + 5 x 8 u
= 3 u + 40 u
= 43 u
= 43 x 0.30
= $12.90
Answer(s): (a) $2.40; (b) $12.90