Oliver had $100 less than Pierre. If Pierre spends $110 and Oliver's mother gave Oliver $390, Pierre will have
14 as much money as Oliver. How much money did Oliver and Pierre have?
| |
Make p the same
(1)x4 = (3) |
Oliver
(1) |
Pierre
(2) |
| Before |
4 u |
1 u |
1 u + 100 |
| Change |
- 440 |
- 110 |
+ 390 |
| After |
4 p |
1 p |
4 p |
Since Oliver had $100 less than Pierre, this means Pierre had $100 more than Oliver.
1 u - 110 = 1 p --- (1)
1 u + 100 + 390 = 4 p
1 u + 490 =
4 p --- (2)
Make p the same.
(1)
x4
4 u - 440 =
4 p --- (3)
(3) = (2)
4 u - 440 = 1 u + 490
4 u - 1 u = 490 + 440
3 u = 930
1 u = 930 ÷ 3 = 310
Total amount that Oliver and Pierre had
= 1 u + 1 u + 100
= 2 u + 100
= 2 x 310 + 100
= 620 + 100
= $720
Answer(s): $720
