Adam buys a sticker for $7.
He also buys a marble.
The marble costs 3 times as much as the sticker.
- How much less does the marble cost than the sticker?
- How much does he spend altogether?
- How much are 3 marbles?
- How much are 4 marbles and 2 stickers?
(a)
Choose the cheaper item to be 1 u.
The marble costs 3 times as much as the sticker.
The sticker is cheaper.
Cost of the sticker = 1 u = $7
Cost of the marble = 3 u
Amount that the sticker costs less than the marble
= 3 u - 1 u
= 2 u
= 2 x 7
= $14
(b)
Total amount that Adam spends
= 1 u + 3 u
= 4 u
= 4 x 7
= $28
(c)
Cost of 3 marbles
= 3 x 3 u
= 9 u
= 9 x 7
= $63
(d )
Cost of 4 marbles and 2 stickers
= 4 x 3 u + 2 x 1 u
= 12 u + 2 u
= 14 u
= 14 x 7
= $98
Answer(s): (a) $14; (b) $28; (c) $63; (d) $98