PSLE Linda saved $120 in November. This amount was a 40% decrease from what she saved in October. The amount she saved in December was a 40% increase from what she saved in November.
- What was the total amount that Linda saved from October to December?
- What was the percentage decrease in the amount Linda saved in December compared to October?
|
Savings |
October |
100% |
|
Change |
- 40% |
|
November |
60% |
100 u |
Change |
|
+ 40 u |
December |
|
140 u |
(a)
Savings in October = 100%
Savings in November = 100% - 40% = 60%
60% = 120
1% = 120 ÷ 60 = 2
Savings in October
= 100%
= 100 x 2
= $200
Savings in November = 100 u
Savings in December = 100 u + 40 u = 140 u
100 u = 120
1 u = 120 ÷ 100 = 1.2
Savings in December
= 140 u
= 140 x 1.2
= $168
Total savings from October to December
= 200 + 120 + 168
= $488
(b)
Decrease in savings in December compared to October
= 200 - 168
= $32
Percentage decrease
=
Decrease in savingsSavings in October x 100%
=
32200 x 100%
= 16%
Answer(s): (a) $488; (b) 16%