Perry's and Shiyun's monthly allowances were the same at first. Perry's allowance increased by 20% while Shiyun's decreased by 10%. Given that Perry's allowance would increase by another 25% if he had received $729 more from his Fathers, find the difference in the children's monthly allowances.
| |
Perry |
Shiyun |
| Before |
1 u |
1 u |
| Change 1 |
+ 0.2 u |
- 0.1 u |
| After 1 |
1.2 u |
0.9 u |
| Change 2 |
+ 0.3 u |
No change |
| After 2 |
1.5 u |
0.9 u |
Increase in Perry's allowance
= 20% x 1 u
=
20100 x 1 u
= 0.2 u
Decrease in Shiyun's allowance
= 10% x 1 u
=
10100 x 1 u
= 0.1 u
Increase in Perry's allowance if his Fathers gave another $729
= 25% x 1.2 u
=
25100 x 1.2 u
= 0.3 u
0.3 u = 729
1 u = 729 ÷ 0.3 = 2430
Difference in the allowance between Perry and Shiyun
= 1.2 u - 0.9 u
= 0.3 u
= 0.3 x 2430
= $729
Answer(s): $729
