PSLE Linda spent $480 in November. This amount was a 20% increase from what she spent in October. The amount she spent in December was a 30% 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 |
|
- 30 u |
December |
|
70 u |
(a)
Spending in October = 100%
Spending in November = 100% + 20% = 120%
120% = 480
1% = 480 ÷ 120 = 4
Spending in October
= 100%
= 100 x 4
= $400
Spending in November = 100 u
Spending in December = 100 u - 30 u = 70 u
100 u = 480
1 u = 480 ÷ 100 = 4.8
Spending in December
= 70 u
= 70 x 4.8
= $336
Total spending from October to December
= 400 + 480 + 336
= $1216
(b)
Decrease in spending in December compared to October
= 400 - 336
= $64
Percentage decrease
=
Decrease in spendingSpending in October x 100%
=
64400 x 100%
= 16%
Answer(s): (a) $1216; (b) 16%