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

1. Half of the rulers sold by Stationery Kiosk A were purple rulers. How many purple rulers did Stationery Kiosk A sell?
2. Which colour(s) of rulers 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 July, Stationery Kiosk B sold 20 less green rulers than the number of green rulers sold in June. What was the percentage increase in the number of green rulers sold by Stationery Kiosk B from June to July?

(a)
Number of blue rulers sold in Stationery Kiosk A = 40
Number of green rulers sold in Stationery Kiosk A = 180
Number of pink rulers sold in Stationery Kiosk A = 180

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

Number of purple rulers sold in Stationery Kiosk A
= 180 + 180 + 40
= 400

(b)
Number of blue rulers sold in Stationery Kiosk A = 40 (Less) 
Number of blue rulers sold in Stationery Kiosk B = 140

Number of green rulers sold in Stationery Kiosk A = 180 (More)
Number of green rulers sold in Stationery Kiosk B = 100

Number of pink rulers sold in Stationery Kiosk A = 180 (Equal)
Number of pink rulers sold in Stationery Kiosk B = 180

Number of purple rulers sold in Stationery Kiosk A = 400 (More) 
Number of purple rulers sold in Stationery Kiosk B = 200 

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

(c)
Percentage decrease in the number of green rulers sold by Stationery Kiosk B from June to July
= ²⁰₁₀₀ x 100%
= ¹₅ x 100%
= 20%

Answer(s): (a) 400; (b) B; (c) 20%