At a shop, Mary paid $71 for 1 button and 3 marbles. The button cost $3 more than each marble.
- How much is 1 marble?
- How much is 1 button?
(a)
Cost of 1 marble = 1 u
Cost of 3 marbles = 3 u
Cost of 1 button = 1 u + 3
Total cost of 1 button and 3 marbles
= 3 u + 1 u + 3
= 4 u + 3
4 u + 3 = 71
4 u = 71 - 3
4 u = 68
1 u = 68 ÷ 4 = 17
Cost of 1 marble
= 1 u
= $17
(b)
Cost of 1 button
= 1 u + 3
= 17 + 3
= $20
Answer(s): (a) $17; (b) $20