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

1. Half of the rulers sold by Bookstore X were pink rulers. How many pink rulers did Bookstore X sell?
2. Which colour(s) of rulers did Bookstore X sell less than Bookstore Y? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In October, Bookstore Y sold 5 more purple rulers than the number of purple rulers sold in September. What was the percentage increase in the number of purple rulers sold by Bookstore Y from September to October?

(a)
Number of purple rulers sold in Bookstore X = 175
Number of blue rulers sold in Bookstore X = 100
Number of green rulers sold in Bookstore X = 125

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

Number of pink rulers sold in Bookstore X
= 175 + 100 + 125
= 400

(b)
Number of purple rulers sold in Bookstore X = 175 (More)
Number of purple rulers sold in Bookstore Y = 125

Number of blue rulers sold in Bookstore X = 100 (Equal)
Number of blue rulers sold in Bookstore Y = 100

Number of green rulers sold in Bookstore X = 125 (Less) 
Number of green rulers sold in Bookstore Y = 200

Number of pink rulers sold in Bookstore X = 400 (More) 
Number of pink rulers sold in Bookstore Y = 75 

Colour(s) of rulers that Bookstore X sold less than Bookstore Y = Green (G)

(c)
Percentage increase in the number of purple rulers sold by Bookstore Y from September to October
= ⁵₁₂₅ x 100%
= ¹₂₅ x 100%
= 4%

Answer(s): (a) 400; (b) G; (c) 4%