Three schoolmates spent a total of $99. Tiffany spent $9 more than Yen and Cathy spent $12 more than Tiffany.
- How much money did Yen spend?
- How much money did Cathy spend?
(a)
Amount that Yen spent = 1 u
Amount that Tiffany spent = 1 u + 9
Amount that Cathy spent = 1 u + 9 + 12 = 1 u + 21
Total amount that they spent
= 1 u + 1 u + 9 + 1 u + 21
= 3 u + 30
3 u + 30 = 99
3 u = 99 - 30
3 u = 69
1 u = 69 ÷ 3 = $23
Amount that Yen spent
= 1 u
= 23
(b)
Amount that Cathy spent
= 1 u + 21
= 23 + 21
= $44
Answer(s): (a) $23; (b) $44
