PSLE
Bookstores M and N sell rulers of four colours. The bar graphs show the number of rulers sold by each shop in August. The bar for the number pink rulers sold by Bookstore M has not been drawn.

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

(a)
Number of blue rulers sold in Bookstore M = 175
Number of orange rulers sold in Bookstore M = 175
Number of yellow rulers sold in Bookstore M = 25

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

Number of pink rulers sold in Bookstore M
= 175 + 175 + 25
= 375

(b)
Number of blue rulers sold in Bookstore M = 175 (More)
Number of blue rulers sold in Bookstore N = 125

Number of orange rulers sold in Bookstore M = 175 (Equal)
Number of orange rulers sold in Bookstore N = 175

Number of yellow rulers sold in Bookstore M = 25 (Less) 
Number of yellow rulers sold in Bookstore N = 225

Number of pink rulers sold in Bookstore M = 375 (More) 
Number of pink rulers sold in Bookstore N = 150 

Colour(s) of rulers that Bookstore M sold less than Bookstore N = Yellow (Y)

(c)
Percentage increase in the number of blue rulers sold by Bookstore N from August to September
= ³⁰₁₂₅ x 100%
= ⁶₂₅ x 100%
= 24%

Answer(s): (a) 375; (b) Y; (c) 24%