PSLE Linda spent $490 in November. This amount was a 30% decrease from what she spent in October. The amount she spent in December was a 50% 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 |
- 30% |
|
November |
70% |
100 u |
Change |
|
+ 50 u |
December |
|
150 u |
(a)
Spending in October = 100%
Spending in November = 100% - 30% = 70%
70% = 490
1% = 490 ÷ 70 = 7
Spending in October
= 100%
= 100 x 7
= $700
Spending in November = 100 u
Spending in December = 100 u + 50 u = 150 u
100 u = 490
1 u = 490 ÷ 100 = 4.9
Spending in December
= 150 u
= 150 x 4.9
= $735
Total spending from October to December
= 700 + 490 + 735
= $1925
(b)
Increase in spending in December compared to October
= 735 - 700
= $35
Percentage increase
=
Increase in spendingSpending in October x 100%
=
35700 x 100%
= 5%
Answer(s): (a) $1925; (b) 5%