David's salary to Charlie's salary is 5 : 6. The former saves $1750 while the latter saves $1820. If Charlie's spending to David's spending is in the ratio of 5 : 3, what are David's and Charlie's salaries respectively?
- David
- Charlie
| David's salary |
Charlie's salary |
| 5 u |
6 u |
| Savings |
Spending |
Savings |
Spending |
| $1750 |
3 p |
$1820 |
5 p |
1750 + 3 p = 5 u --- (1)
1820 + 5 p = 6 u --- (2)
Make p the same.
(1)
x 58750 +
15 p = 25 u
15 p = 25 u - 8750 --- (3)
(2)
x 35460 +
15 p = 18 u
15 p = 18 u - 5460 --- (4)
(3) = (4)
25 u - 8750 = 18 u - 5460
25 u - 18 u = 8750 - 5460
7 u = 3290
1 u = 3290 ÷ 7 = 470
(a)
David's salary
= 5 u
= 5 x 470
= $2350
(b)
Charlie's salary
= 6 u
= 6 x 470
= $2820
Answer(s): (a) $2350; (b) $2820
