PSLE
Linda saved $1200 in August. This amount was a 20% increase from what she saved in July. The amount she saved in September was a 10% decrease from what she saved in August.

1. What was the total amount that Linda saved from July to September?
2. What was the percentage increase in the amount Linda saved in September compared to July?

	Savings
July	100%
Change	+ 20%
August	120%	100 u
Change		- 10 u
September		90 u

(a)
Savings in July = 100%
Savings in August = 100% + 20% = 120%

120% = 1200

1% = 1200 ÷ 120 = 10

Savings in July
= 100% 
= 100 x 10
= $1000

Savings in August = 100 u
Savings in September = 100 u - 10 u = 90 u 

100 u = 1200

1 u = 1200 ÷ 100 = 12

Savings in September
= 90 u
= 90 x 12
= $1080

Total savings from July to September
= 1000 + 1200 + 1080
= $3280

(b)
Increase in savings in September compared to July
= 1080 - 1000
= $80

Percentage increase
= ^{Increase in savings}_{Savings in July} x 100%
= ⁸⁰₁₀₀₀ x 100%
= 8%

Answer(s): (a) $3280; (b) 8%