PSLE
Linda spent $420 in February. This amount was a 40% increase from what she spent in January. The amount she spent in March was a 40% decrease from what she spent in February.

1. What was the total amount that Linda spent from January to March?
2. What was the percentage decrease in the amount Linda spent in March compared to January?

	Spending
January	100%
Change	+ 40%
February	140%	100 u
Change		- 40 u
March		60 u

(a)
Spending in January = 100%
Spending in February = 100% + 40% = 140%

140% = 420

1% = 420 ÷ 140 = 3

Spending in January
= 100% 
= 100 x 3
= $300

Spending in February = 100 u
Spending in March = 100 u - 40 u = 60 u 

100 u = 420

1 u = 420 ÷ 100 = 4.2

Spending in March
= 60 u
= 60 x 4.2
= $252

Total spending from January to March
= 300 + 420 + 252
= $972

(b)
Decrease in spending in March compared to January
= 300 - 252 
= $48

Percentage decrease
= ^{Decrease in spending}_{Spending in January} x 100%
= ⁴⁸₃₀₀ x 100%
= 16%

Answer(s): (a) $972; (b) 16%