Adam buys a bead for $3.
He also buys a marble.
The marble costs 3 times as much as the bead.
- How much less does the marble cost than the bead?
- How much does he spend altogether?
- How much are 4 marbles?
- How much are 2 marbles and 2 beads?
(a)
Choose the cheaper item to be 1 u.
The marble costs 3 times as much as the bead.
The bead is cheaper.
Cost of the bead = 1 u = $3
Cost of the marble = 3 u
Amount that the bead costs less than the marble
= 3 u - 1 u
= 2 u
= 2 x 3
= $6
(b)
Total amount that Adam spends
= 1 u + 3 u
= 4 u
= 4 x 3
= $12
(c)
Cost of 4 marbles
= 4 x 3 u
= 12 u
= 12 x 3
= $36
(d )
Cost of 2 marbles and 2 beads
= 2 x 3 u + 2 x 1 u
= 6 u + 2 u
= 8 u
= 8 x 3
= $24
Answer(s): (a) $6; (b) $12; (c) $36; (d) $24