Adam buys a marble for $8.
He also buys a bead.
The marble costs 4 times as much as the bead.
- How much less does the bead cost than the marble?
- How much does he spend altogether?
- How much are 2 beads?
- What is the difference in cost between 3 marbles and 2 beads?
(a)
Choose the cheaper item to be 1 u.
The marble costs 4 times as much as the bead.
The bead is cheaper.
Cost of the bead = 1 u
Cost of the marble = 4 u = $8
4 u = 8
1 u = 8 ÷ 4 = 2
Amount that the bead costs less than the marble
= 4 u - 1 u
= 3 u
= 3 x 2
= $6
(b)
Total amount that Adam spends
= 1 u + 4 u
= 5 u
= 5 x 2
= $10
(c)
Cost of 2 beads
= 2 x 1 u
= 2 u
= 2 x 2
= $4
(d )
Difference in the cost between 6 marbles and 2 beads
= (3 x 4 u) - (2 x 1 u)
= 12 u - 2 u
= 10 u
= 10 x 2
= $20
Answer(s): (a) $6; (b) $10; (c) $4; (d) $20