PSLE
Stationery Kiosks Y and Z sell highlighters of four colours. The bar graphs show the number of highlighters sold by each shop in March. The bar for the number blue highlighters sold by Stationery Kiosk Y has not been drawn.

1. Half of the highlighters sold by Stationery Kiosk Y were blue highlighters. How many blue highlighters did Stationery Kiosk Y sell?
2. Which colour(s) of highlighters did Stationery Kiosk Y sell less than Stationery Kiosk Z? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In April, Stationery Kiosk Z sold 10 more purple highlighters than the number of purple highlighters sold in March. What was the percentage increase in the number of purple highlighters sold by Stationery Kiosk Z from March to April?

(a)
Number of purple highlighters sold in Stationery Kiosk Y = 225
Number of orange highlighters sold in Stationery Kiosk Y = 175
Number of green highlighters sold in Stationery Kiosk Y = 75

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

Number of blue highlighters sold in Stationery Kiosk Y
= 225 + 175 + 75
= 475

(b)
Number of purple highlighters sold in Stationery Kiosk Y = 225 (More)
Number of purple highlighters sold in Stationery Kiosk Z = 125

Number of orange highlighters sold in Stationery Kiosk Y = 175 (Equal)
Number of orange highlighters sold in Stationery Kiosk Z = 175

Number of green highlighters sold in Stationery Kiosk Y = 75 (Less) 
Number of green highlighters sold in Stationery Kiosk Z = 250

Number of blue highlighters sold in Stationery Kiosk Y = 475 (More) 
Number of blue highlighters sold in Stationery Kiosk Z = 200 

Colour(s) of highlighters that Stationery Kiosk Y sold less than Stationery Kiosk Z = Green (G)

(c)
Percentage increase in the number of purple highlighters sold by Stationery Kiosk Z from March to April
= ¹⁰₁₂₅ x 100%
= ²₂₅ x 100%
= 8%

Answer(s): (a) 475; (b) G; (c) 8%