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

1. Half of the rulers sold by Stationery Kiosk K were purple rulers. How many purple rulers did Stationery Kiosk K sell?
2. Which colour(s) of rulers did Stationery Kiosk K sell less than Stationery Kiosk L? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In June, Stationery Kiosk L sold 15 more green rulers than the number of green rulers sold in May. What was the percentage increase in the number of green rulers sold by Stationery Kiosk L from May to June?

(a)
Number of green rulers sold in Stationery Kiosk K = 200
Number of blue rulers sold in Stationery Kiosk K = 200
Number of yellow rulers sold in Stationery Kiosk K = 40

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

Number of purple rulers sold in Stationery Kiosk K
= 200 + 200 + 40
= 440

(b)
Number of green rulers sold in Stationery Kiosk K = 200 (More)
Number of green rulers sold in Stationery Kiosk L = 60

Number of blue rulers sold in Stationery Kiosk K = 200 (Equal)
Number of blue rulers sold in Stationery Kiosk L = 200

Number of yellow rulers sold in Stationery Kiosk K = 40 (Less) 
Number of yellow rulers sold in Stationery Kiosk L = 160

Number of purple rulers sold in Stationery Kiosk K = 440 (More) 
Number of purple rulers sold in Stationery Kiosk L = 140 

Colour(s) of rulers that Stationery Kiosk K sold less than Stationery Kiosk L = Yellow (Y)

(c)
Percentage increase in the number of green rulers sold by Stationery Kiosk L from May to June
= ¹⁵₆₀ x 100%
= ¹₄ x 100%
= 25%

Answer(s): (a) 440; (b) Y; (c) 25%