PSLE
Stationery Kiosks A and B sell highlighters of four colours. The bar graphs show the number of highlighters sold by each shop in November. The bar for the number purple highlighters sold by Stationery Kiosk A has not been drawn.

1. Half of the highlighters sold by Stationery Kiosk A were purple highlighters. How many purple highlighters did Stationery Kiosk A sell?
2. Which colour(s) of highlighters did Stationery Kiosk A sell less than Stationery Kiosk B? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In December, Stationery Kiosk B sold 45 less orange highlighters than the number of orange highlighters sold in November. What was the percentage increase in the number of orange highlighters sold by Stationery Kiosk B from November to December?

(a)
Number of blue highlighters sold in Stationery Kiosk A = 20
Number of orange highlighters sold in Stationery Kiosk A = 200
Number of green highlighters sold in Stationery Kiosk A = 140

Since purple highlighters sold in Stationery Kiosk A is half of the highlighters sold by Stationery Kiosk A, the total of orange highlighters, green highlighters and blue highlighters is equal to purple highlighters.

Number of purple highlighters sold in Stationery Kiosk A
= 200 + 140 + 20
= 360

(b)
Number of blue highlighters sold in Stationery Kiosk A = 20 (Less) 
Number of blue highlighters sold in Stationery Kiosk B = 160

Number of orange highlighters sold in Stationery Kiosk A = 200 (More)
Number of orange highlighters sold in Stationery Kiosk B = 100

Number of green highlighters sold in Stationery Kiosk A = 140 (Equal)
Number of green highlighters sold in Stationery Kiosk B = 140

Number of purple highlighters sold in Stationery Kiosk A = 360 (More) 
Number of purple highlighters sold in Stationery Kiosk B = 180 

Colour(s) of highlighters that Stationery Kiosk A sold less than Stationery Kiosk B = Blue (B)

(c)
Percentage decrease in the number of orange highlighters sold by Stationery Kiosk B from November to December
= ⁴⁵₁₀₀ x 100%
= ⁹₂₀ x 100%
= 45%

Answer(s): (a) 360; (b) B; (c) 45%