PSLE Linda spent $1080 in September. This amount was a 20% increase from what she spent in August. The amount she spent in October was a 10% decrease from what she spent in September.
- What was the total amount that Linda spent from August to October?
- What was the percentage increase in the amount Linda spent in October compared to August?
|
Spending |
August |
100% |
|
Change |
+ 20% |
|
September |
120% |
100 u |
Change |
|
- 10 u |
October |
|
90 u |
(a)
Spending in August = 100%
Spending in September = 100% + 20% = 120%
120% = 1080
1% = 1080 ÷ 120 = 9
Spending in August
= 100%
= 100 x 9
= $900
Spending in September = 100 u
Spending in October = 100 u - 10 u = 90 u
100 u = 1080
1 u = 1080 ÷ 100 = 10.8
Spending in October
= 90 u
= 90 x 10.8
= $972
Total spending from August to October
= 900 + 1080 + 972
= $2952
(b)
Increase in spending in October compared to August
= 972 - 900
= $72
Percentage increase
=
Increase in spendingSpending in August x 100%
=
72900 x 100%
= 8%
Answer(s): (a) $2952; (b) 8%