Adam pays $1.60 for a marble and a bead.
The marble costs 3 times as much as the bead.
- What is the cost of 1 marble?
- How much is the cost of 3 beads and 2 marbles?
(a)
Cost of a bead = 1 u
Cost of a marble = 3 u
Total cost of a bead and a marble
= 1 u + 3 u
= 4 u
4 u = 1.60
1 u = 1.60 ÷ 4 = 0.40
Cost of the marble
= 3 u
= 3 x 0.40
= $1.20
(b)
Cost of 3 beads and 2 marbles
= 3 x 1 u + 2 x 3 u
= 3 u + 6 u
= 9 u
= 9 x 0.40
= $3.60
Answer(s): (a) $1.20; (b) $3.60