Justin had $90 more than Mary. After Justin spent 20% of his money and Mary spent 70% of her money, they still had $380 left altogether.
- How much did Justin have left in the end?
- Express the amount of money Mary had left as a fraction of the amount of money Justin had in the end. (Give your answer in the simplest form)
| |
Justin |
Mary |
| Before |
10 u + 90 |
10 u |
| Change |
- 2 u - 18 |
- 7 u |
| After |
8 u + 72 |
3 u |
20% =
20100 =
210 70% =
70100 =
710Total amount that Justin and Mary had in the end
= 8 u + 72 + 3 u
= 11 u + 72
11 u + 72 = 380
8 u + 3 u = 380 - 72
11 u = 308
1 u = 308 ÷ 11 = 28
Amount that Justin had in the end
= 8 u + 72
= 8 x 28 + 72
= 224 + 72
= $296
(b)
Amount that the Mary had in the end
= 1 u
= $28
Fraction of the amount that Mary had left as a fraction of the amount that Justin had in the end
=
28296=
774 Answer(s): (a) $296; (b)
774 
