PSLE
Bookstores P and Q sell rulers of four colours. The bar graphs show the number of rulers sold by each shop in February. The bar for the number green rulers sold by Bookstore P has not been drawn.

1. Half of the rulers sold by Bookstore P were green rulers. How many green rulers did Bookstore P sell?
2. Which colour(s) of rulers did Bookstore P sell less than Bookstore Q? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In March, Bookstore Q sold 30 more blue rulers than the number of blue rulers sold in February. What was the percentage increase in the number of blue rulers sold by Bookstore Q from February to March?

(a)
Number of blue rulers sold in Bookstore P = 80
Number of yellow rulers sold in Bookstore P = 60
Number of orange rulers sold in Bookstore P = 30

Since green rulers sold in Bookstore P is half of the rulers sold by Bookstore P, the total of blue rulers, yellow rulers and orange rulers is equal to green rulers.

Number of green rulers sold in Bookstore P
= 80 + 60 + 30
= 170

(b)
Number of blue rulers sold in Bookstore P = 80 (More)
Number of blue rulers sold in Bookstore Q = 50

Number of yellow rulers sold in Bookstore P = 60 (Equal)
Number of yellow rulers sold in Bookstore Q = 60

Number of orange rulers sold in Bookstore P = 30 (Less) 
Number of orange rulers sold in Bookstore Q = 60

Number of green rulers sold in Bookstore P = 170 (More) 
Number of green rulers sold in Bookstore Q = 70 

Colour(s) of rulers that Bookstore P sold less than Bookstore Q = Orange (O)

(c)
Percentage increase in the number of blue rulers sold by Bookstore Q from February to March
= ³⁰₅₀ x 100%
= ³₅ x 100%
= 60%

Answer(s): (a) 170; (b) O; (c) 60%