PSLE Linda spent $945 in November. This amount was a 5% increase from what she spent in October. The amount she spent in December was a 20% 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 |
+ 5% |
|
November |
105% |
100 u |
Change |
|
- 20 u |
December |
|
80 u |
(a)
Spending in October = 100%
Spending in November = 100% + 5% = 105%
105% = 945
1% = 945 ÷ 105 = 9
Spending in October
= 100%
= 100 x 9
= $900
Spending in November = 100 u
Spending in December = 100 u - 20 u = 80 u
100 u = 945
1 u = 945 ÷ 100 = 9.45
Spending in December
= 80 u
= 80 x 9.45
= $756
Total spending from October to December
= 900 + 945 + 756
= $2601
(b)
Decrease in spending in December compared to October
= 900 - 756
= $144
Percentage decrease
=
Decrease in spendingSpending in October x 100%
=
144900 x 100%
= 16%
Answer(s): (a) $2601; (b) 16%