PSLE
Bookstores T and U sell highlighters of four colours. The bar graphs show the number of highlighters sold by each shop in May. The bar for the number blue highlighters sold by Bookstore T has not been drawn.

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

(a)
Number of green highlighters sold in Bookstore T = 175
Number of purple highlighters sold in Bookstore T = 150
Number of yellow highlighters sold in Bookstore T = 50

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

Number of blue highlighters sold in Bookstore T
= 175 + 150 + 50
= 375

(b)
Number of green highlighters sold in Bookstore T = 175 (More)
Number of green highlighters sold in Bookstore U = 25

Number of purple highlighters sold in Bookstore T = 150 (Equal)
Number of purple highlighters sold in Bookstore U = 150

Number of yellow highlighters sold in Bookstore T = 50 (Less) 
Number of yellow highlighters sold in Bookstore U = 150

Number of blue highlighters sold in Bookstore T = 375 (More) 
Number of blue highlighters sold in Bookstore U = 125 

Colour(s) of highlighters that Bookstore T sold less than Bookstore U = Yellow (Y)

(c)
Percentage increase in the number of green highlighters sold by Bookstore U from May to June
= ²⁰₂₅ x 100%
= ⁴₅ x 100%
= 80%

Answer(s): (a) 375; (b) Y; (c) 80%