PSLE David was given a fixed amount of allowance each month. In May, he spent $20 and saved the rest. In June, he spent 10% less and his savings increased by 20%. How much was David's allowance for each month?
|
Spending (%) |
Savings (u) |
Before
|
100% $20 |
100 u
|
Change |
- 10% |
+ 20 u |
After |
90% |
120 u |
100% of spending = 20
1% of spending = 20 ÷ 100 = 0.2
10% of spending = 10% x 20 = 2
10% of spending = 20 u of savings
20 u of savings = 2
1 u of savings = 2 ÷ 20 = 0.1
100 u of savings = 100 x 0.1 = 10
David's allowance for each month
= 100% of spending + 100 u of savings
= 20 + 10
= $30
Answer(s): $30