PSLE
Stores P and Q sell highlighters of four colours. The bar graphs show the number of highlighters sold by each shop in March. The bar for the number purple highlighters sold by Store P has not been drawn.

1. Half of the highlighters sold by Store P were purple highlighters. How many purple highlighters did Store P sell?
2. Which colour(s) of highlighters did Store P sell less than Store Q? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In April, Store Q sold 20 less pink highlighters than the number of pink highlighters sold in March. What was the percentage increase in the number of pink highlighters sold by Store Q from March to April?

(a)
Number of blue highlighters sold in Store P = 60
Number of pink highlighters sold in Store P = 160
Number of yellow highlighters sold in Store P = 180

Since purple highlighters sold in Store P is half of the highlighters sold by Store P, the total of pink highlighters, yellow highlighters and blue highlighters is equal to purple highlighters.

Number of purple highlighters sold in Store P
= 160 + 180 + 60
= 400

(b)
Number of blue highlighters sold in Store P = 60 (Less) 
Number of blue highlighters sold in Store Q = 160

Number of pink highlighters sold in Store P = 160 (More)
Number of pink highlighters sold in Store Q = 100

Number of yellow highlighters sold in Store P = 180 (Equal)
Number of yellow highlighters sold in Store Q = 180

Number of purple highlighters sold in Store P = 400 (More) 
Number of purple highlighters sold in Store Q = 160 

Colour(s) of highlighters that Store P sold less than Store Q = Blue (B)

(c)
Percentage decrease in the number of pink highlighters sold by Store Q from March to April
= ²⁰₁₀₀ x 100%
= ¹₅ x 100%
= 20%

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