PSLE Linda saved $770 in November. This amount was a 10% increase from what she saved in October. The amount she saved in December was a 30% 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 |
+ 10% |
|
November |
110% |
100 u |
Change |
|
- 30 u |
December |
|
70 u |
(a)
Savings in October = 100%
Savings in November = 100% + 10% = 110%
110% = 770
1% = 770 ÷ 110 = 7
Savings in October
= 100%
= 100 x 7
= $700
Savings in November = 100 u
Savings in December = 100 u - 30 u = 70 u
100 u = 770
1 u = 770 ÷ 100 = 7.7
Savings in December
= 70 u
= 70 x 7.7
= $539
Total savings from October to December
= 700 + 770 + 539
= $2009
(b)
Decrease in savings in December compared to October
= 700 - 539
= $161
Percentage decrease
=
Decrease in savingsSavings in October x 100%
=
161700 x 100%
= 23%
Answer(s): (a) $2009; (b) 23%