PSLE Billy was given a fixed amount of allowance each month. In July, he spent $50 and saved the rest. In August, he spent 20% less and his savings increased by 40%. How much was Billy's allowance for each month?
|
Spending (%) |
Savings (u) |
Before
|
100% $50 |
100 u
|
Change |
- 20% |
+ 40 u |
After |
80% |
140 u |
100% of spending = 50
1% of spending = 50 ÷ 100 = 0.5
20% of spending = 20% x 50 = 10
20% of spending = 40 u of savings
40 u of savings = 10
1 u of savings = 10 ÷ 40 = 0.25
100 u of savings = 100 x 0.25 = 25
Billy's allowance for each month
= 100% of spending + 100 u of savings
= 50 + 25
= $75
Answer(s): $75