PSLE Linda saved $450 in November. This amount was a 10% decrease from what she saved in October. The amount she saved in December was a 20% increase from what she saved in November.
- What was the total amount that Linda saved from October to December?
- What was the percentage increase in the amount Linda saved in December compared to October?
|
Savings |
October |
100% |
|
Change |
- 10% |
|
November |
90% |
100 u |
Change |
|
+ 20 u |
December |
|
120 u |
(a)
Savings in October = 100%
Savings in November = 100% - 10% = 90%
90% = 450
1% = 450 ÷ 90 = 5
Savings in October
= 100%
= 100 x 5
= $500
Savings in November = 100 u
Savings in December = 100 u + 20 u = 120 u
100 u = 450
1 u = 450 ÷ 100 = 4.5
Savings in December
= 120 u
= 120 x 4.5
= $540
Total savings from October to December
= 500 + 450 + 540
= $1490
(b)
Increase in savings in December compared to October
= 540 - 500
= $40
Percentage increase
=
Increase in savingsSavings in October x 100%
=
40500 x 100%
= 8%
Answer(s): (a) $1490; (b) 8%