PSLE Billy was given a fixed amount of allowance each month. In January, he spent $40 and saved the rest. In February, he spent 30% less and his savings increased by 10%. How much was Billy's allowance for each month?
|
Spending (%) |
Savings (u) |
Before
|
100% $40 |
100 u
|
Change |
- 30% |
+ 10 u |
After |
70% |
110 u |
100% of spending = 40
1% of spending = 40 ÷ 100 = 0.4
30% of spending = 30% x 40 = 12
30% of spending = 10 u of savings
10 u of savings = 12
1 u of savings = 12 ÷ 10 = 1.2
100 u of savings = 100 x 1.2 = 120
Billy's allowance for each month
= 100% of spending + 100 u of savings
= 40 + 120
= $160
Answer(s): $160