PSLE Linda spent $910 in November. This amount was a 30% 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 increase in the amount Linda spent in December compared to October?
|
Spending |
October |
100% |
|
Change |
+ 30% |
|
November |
130% |
100 u |
Change |
|
- 20 u |
December |
|
80 u |
(a)
Spending in October = 100%
Spending in November = 100% + 30% = 130%
130% = 910
1% = 910 ÷ 130 = 7
Spending in October
= 100%
= 100 x 7
= $700
Spending in November = 100 u
Spending in December = 100 u - 20 u = 80 u
100 u = 910
1 u = 910 ÷ 100 = 9.1
Spending in December
= 80 u
= 80 x 9.1
= $728
Total spending from October to December
= 700 + 910 + 728
= $2338
(b)
Increase in spending in December compared to October
= 728 - 700
= $28
Percentage increase
=
Increase in spendingSpending in October x 100%
=
28700 x 100%
= 4%
Answer(s): (a) $2338; (b) 4%