PSLE Sam was given a fixed amount of allowance each month. In September, he spent $390 and saved the rest. In October, he spent 30% more and his savings decreased by 10%. How much was Sam's allowance for each month?
|
Spending (%) |
Savings (u) |
Before |
100% $$(n80 |
100 u |
Change |
+ 30% |
- 10 u |
After |
130% |
90 u |
100% of spending = 390
1% of spending = 390 ÷ 100 = 3.9
30% of spending = 30% x 390 = 117
30% of spending = 10 u of savings
10 u of savings = 117
1 u of savings = 117 ÷ 10 = 11.7
100 u of savings = 100 x 11.7 = 1170
Sam's allowance for each month
= 100% of spending + 100 u of savings
= 390 + 1170
= $1560
Answer(s): $1560