PSLE Linda spent $1080 in November. This amount was a 20% increase from what she spent in October. The amount she spent in December was a 40% decrease from what she spent in November.
- What was the total amount that Linda spent from October to December?
- What was the percentage decrease in the amount Linda spent in December compared to October?
|
Spending |
October |
100% |
|
Change |
+ 20% |
|
November |
120% |
100 u |
Change |
|
- 40 u |
December |
|
60 u |
(a)
Spending in October = 100%
Spending in November = 100% + 20% = 120%
120% = 1080
1% = 1080 ÷ 120 = 9
Spending in October
= 100%
= 100 x 9
= $900
Spending in November = 100 u
Spending in December = 100 u - 40 u = 60 u
100 u = 1080
1 u = 1080 ÷ 100 = 10.8
Spending in December
= 60 u
= 60 x 10.8
= $648
Total spending from October to December
= 900 + 1080 + 648
= $2628
(b)
Decrease in spending in December compared to October
= 900 - 648
= $252
Percentage decrease
=
Decrease in spendingSpending in October x 100%
=
252900 x 100%
= 28%
Answer(s): (a) $2628; (b) 28%