PSLE
Bookstores K and L sell highlighters of four colours. The bar graphs show the number of highlighters sold by each shop in October. The bar for the number pink highlighters sold by Bookstore K has not been drawn.

1. Half of the highlighters sold by Bookstore K were pink highlighters. How many pink highlighters did Bookstore K sell?
2. Which colour(s) of highlighters did Bookstore K sell less than Bookstore L? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In November, Bookstore L sold 20 more green highlighters than the number of green highlighters sold in October. What was the percentage increase in the number of green highlighters sold by Bookstore L from October to November?

(a)
Number of green highlighters sold in Bookstore K = 160
Number of purple highlighters sold in Bookstore K = 160
Number of blue highlighters sold in Bookstore K = 40

Since pink highlighters sold in Bookstore K is half of the highlighters sold by Bookstore K, the total of green highlighters, purple highlighters and blue highlighters is equal to pink highlighters.

Number of pink highlighters sold in Bookstore K
= 160 + 160 + 40
= 360

(b)
Number of green highlighters sold in Bookstore K = 160 (More)
Number of green highlighters sold in Bookstore L = 40

Number of purple highlighters sold in Bookstore K = 160 (Equal)
Number of purple highlighters sold in Bookstore L = 160

Number of blue highlighters sold in Bookstore K = 40 (Less) 
Number of blue highlighters sold in Bookstore L = 160

Number of pink highlighters sold in Bookstore K = 360 (More) 
Number of pink highlighters sold in Bookstore L = 200 

Colour(s) of highlighters that Bookstore K sold less than Bookstore L = Blue (B)

(c)
Percentage increase in the number of green highlighters sold by Bookstore L from October to November
= ²⁰₄₀ x 100%
= ¹₂ x 100%
= 50%

Answer(s): (a) 360; (b) B; (c) 50%