Charlie had $120 less than Simon. If Simon spends $100 and Charlie's mother gave Charlie $820, Simon will have
15 as much money as Charlie. How much money did Charlie and Simon have?
| |
Make p the same
(1)x5 = (3) |
Charlie
(1) |
Simon
(2) |
| Before |
5 u |
1 u |
1 u + 120 |
| Change |
- 500 |
- 100 |
+ 820 |
| After |
5 p |
1 p |
5 p |
Since Charlie had $120 less than Simon, this means Simon had $120 more than Charlie.
1 u - 100 = 1 p --- (1)
1 u + 120 + 820 = 5 p
1 u + 940 =
5 p --- (2)
Make p the same.
(1)
x5
5 u - 500 =
5 p --- (3)
(3) = (2)
5 u - 500 = 1 u + 940
5 u - 1 u = 940 + 500
4 u = 1440
1 u = 1440 ÷ 4 = 360
Total amount that Charlie and Simon had
= 1 u + 1 u + 120
= 2 u + 120
= 2 x 360 + 120
= 720 + 120
= $840
Answer(s): $840
