PSLE Linda saved $480 in November. This amount was a 20% increase from what she saved in October. The amount she saved in December was a 20% decrease 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 |
+ 20% |
|
November |
120% |
100 u |
Change |
|
- 20 u |
December |
|
80 u |
(a)
Savings in October = 100%
Savings in November = 100% + 20% = 120%
120% = 480
1% = 480 ÷ 120 = 4
Savings in October
= 100%
= 100 x 4
= $400
Savings in November = 100 u
Savings in December = 100 u - 20 u = 80 u
100 u = 480
1 u = 480 ÷ 100 = 4.8
Savings in December
= 80 u
= 80 x 4.8
= $384
Total savings from October to December
= 400 + 480 + 384
= $1264
(b)
Decrease in savings in December compared to October
= 400 - 384
= $16
Percentage decrease
=
Decrease in savingsSavings in October x 100%
=
16400 x 100%
= 4%
Answer(s): (a) $1264; (b) 4%