Adam buys a bead for $6.
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 2 marbles?
- How much are 3 marbles and 3 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 = $6
Cost of the marble = 3 u
Amount that the bead costs less than the marble
= 3 u - 1 u
= 2 u
= 2 x 6
= $12
(b)
Total amount that Adam spends
= 1 u + 3 u
= 4 u
= 4 x 6
= $24
(c)
Cost of 2 marbles
= 2 x 3 u
= 6 u
= 6 x 6
= $36
(d )
Cost of 3 marbles and 3 beads
= 3 x 3 u + 3 x 1 u
= 9 u + 3 u
= 12 u
= 12 x 6
= $72
Answer(s): (a) $12; (b) $24; (c) $36; (d) $72