Billy had $130 less than John. If John spends $50 and Billy's mother gave Billy $620, John will have
15 as much money as Billy. How much money did Billy and John have?
| |
Make p the same
(1)x5 = (3) |
Billy
(1) |
John
(2) |
| Before |
5 u |
1 u |
1 u + 130 |
| Change |
- 250 |
- 50 |
+ 620 |
| After |
5 p |
1 p |
5 p |
Since Billy had $130 less than John, this means John had $130 more than Billy.
1 u - 50 = 1 p --- (1)
1 u + 130 + 620 = 5 p
1 u + 750 =
5 p --- (2)
Make p the same.
(1)
x5
5 u - 250 =
5 p --- (3)
(3) = (2)
5 u - 250 = 1 u + 750
5 u - 1 u = 750 + 250
4 u = 1000
1 u = 1000 ÷ 4 = 250
Total amount that Billy and John had
= 1 u + 1 u + 130
= 2 u + 130
= 2 x 250 + 130
= 500 + 130
= $630
Answer(s): $630
