PSLE
Book Shops U and V sell rulers of four colours. The bar graphs show the number of rulers sold by each shop in May. The bar for the number blue rulers sold by Book Shop U has not been drawn.

1. Half of the rulers sold by Book Shop U were blue rulers. How many blue rulers did Book Shop U sell?
2. Which colour(s) of rulers did Book Shop U sell less than Book Shop V? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In June, Book Shop V sold 15 more green rulers than the number of green rulers sold in May. What was the percentage increase in the number of green rulers sold by Book Shop V from May to June?

(a)
Number of green rulers sold in Book Shop U = 150
Number of yellow rulers sold in Book Shop U = 100
Number of purple rulers sold in Book Shop U = 50

Since blue rulers sold in Book Shop U is half of the rulers sold by Book Shop U, the total of green rulers, yellow rulers and purple rulers is equal to blue rulers.

Number of blue rulers sold in Book Shop U
= 150 + 100 + 50
= 300

(b)
Number of green rulers sold in Book Shop U = 150 (More)
Number of green rulers sold in Book Shop V = 125

Number of yellow rulers sold in Book Shop U = 100 (Equal)
Number of yellow rulers sold in Book Shop V = 100

Number of purple rulers sold in Book Shop U = 50 (Less) 
Number of purple rulers sold in Book Shop V = 250

Number of blue rulers sold in Book Shop U = 300 (More) 
Number of blue rulers sold in Book Shop V = 125 

Colour(s) of rulers that Book Shop U sold less than Book Shop V = Purple (P)

(c)
Percentage increase in the number of green rulers sold by Book Shop V from May to June
= ¹⁵₁₂₅ x 100%
= ³₂₅ x 100%
= 12%

Answer(s): (a) 300; (b) P; (c) 12%