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

1. Half of the highlighters sold by Stationery Kiosk Y were green highlighters. How many green 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 May, Stationery Kiosk Z sold 10 less orange highlighters than the number of orange highlighters sold in April. What was the percentage increase in the number of orange highlighters sold by Stationery Kiosk Z from April to May?

(a)
Number of pink highlighters sold in Stationery Kiosk Y = 20
Number of orange highlighters sold in Stationery Kiosk Y = 80
Number of purple highlighters sold in Stationery Kiosk Y = 90

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

Number of green highlighters sold in Stationery Kiosk Y
= 80 + 90 + 20
= 190

(b)
Number of pink highlighters sold in Stationery Kiosk Y = 20 (Less) 
Number of pink highlighters sold in Stationery Kiosk Z = 60

Number of orange highlighters sold in Stationery Kiosk Y = 80 (More)
Number of orange highlighters sold in Stationery Kiosk Z = 20

Number of purple highlighters sold in Stationery Kiosk Y = 90 (Equal)
Number of purple highlighters sold in Stationery Kiosk Z = 90

Number of green highlighters sold in Stationery Kiosk Y = 190 (More) 
Number of green highlighters sold in Stationery Kiosk Z = 100 

Colour(s) of highlighters that Stationery Kiosk Y sold less than Stationery Kiosk Z = Pink (P)

(c)
Percentage decrease in the number of orange highlighters sold by Stationery Kiosk Z from April to May
= ¹⁰₂₀ x 100%
= ¹₂ x 100%
= 50%

Answer(s): (a) 190; (b) P; (c) 50%