Adam pays $3.20 for a bead and a marble.
The bead costs 3 times as much as the marble.
- What is the cost of 1 bead?
- How much is the cost of 3 marbles and 2 beads?
(a)
Cost of a marble = 1 u
Cost of a bead = 3 u
Total cost of a marble and a bead
= 1 u + 3 u
= 4 u
4 u = 3.20
1 u = 3.20 ÷ 4 = 0.80
Cost of the bead
= 3 u
= 3 x 0.80
= $2.40
(b)
Cost of 3 marbles and 2 beads
= 3 x 1 u + 2 x 3 u
= 3 u + 6 u
= 9 u
= 9 x 0.80
= $7.20
Answer(s): (a) $2.40; (b) $7.20