PSLE Linda spent $720 in November. This amount was a 20% decrease from what she spent in October. The amount she spent in December was a 45% increase from what she spent in November.
- What was the total amount that Linda spent from October to December?
- What was the percentage increase in the amount Linda spent in December compared to October?
|
Spending |
October |
100% |
|
Change |
- 20% |
|
November |
80% |
100 u |
Change |
|
+ 45 u |
December |
|
145 u |
(a)
Spending in October = 100%
Spending in November = 100% - 20% = 80%
80% = 720
1% = 720 ÷ 80 = 9
Spending in October
= 100%
= 100 x 9
= $900
Spending in November = 100 u
Spending in December = 100 u + 45 u = 145 u
100 u = 720
1 u = 720 ÷ 100 = 7.2
Spending in December
= 145 u
= 145 x 7.2
= $1044
Total spending from October to December
= 900 + 720 + 1044
= $2664
(b)
Increase in spending in December compared to October
= 1044 - 900
= $144
Percentage increase
=
Increase in spendingSpending in October x 100%
=
144900 x 100%
= 16%
Answer(s): (a) $2664; (b) 16%