Adam pays $3.60 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 2 beads and 3 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 = 3.60
1 u = 3.60 ÷ 4 = 0.90
Cost of the marble
= 3 u
= 3 x 0.90
= $2.70
(b)
Cost of 2 beads and 3 marbles
= 2 x 1 u + 3 x 3 u
= 2 u + 9 u
= 11 u
= 11 x 0.90
= $9.90
Answer(s): (a) $2.70; (b) $9.90