PSLE
Stores U and V sell post-it-pads of four colours. The bar graphs show the number of post-it-pads sold by each shop in August. The bar for the number yellow post-it-pads sold by Store U has not been drawn.

1. Half of the post-it-pads sold by Store U were yellow post-it-pads. How many yellow post-it-pads did Store U sell?
2. Which colour(s) of post-it-pads did Store U sell less than Store V? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In September, Store V sold 15 more blue post-it-pads than the number of blue post-it-pads sold in August. What was the percentage increase in the number of blue post-it-pads sold by Store V from August to September?

(a)
Number of blue post-it-pads sold in Store U = 140
Number of green post-it-pads sold in Store U = 160
Number of orange post-it-pads sold in Store U = 80

Since yellow post-it-pads sold in Store U is half of the post-it-pads sold by Store U, the total of blue post-it-pads, green post-it-pads and orange post-it-pads is equal to yellow post-it-pads.

Number of yellow post-it-pads sold in Store U
= 140 + 160 + 80
= 380

(b)
Number of blue post-it-pads sold in Store U = 140 (More)
Number of blue post-it-pads sold in Store V = 100

Number of green post-it-pads sold in Store U = 160 (Equal)
Number of green post-it-pads sold in Store V = 160

Number of orange post-it-pads sold in Store U = 80 (Less) 
Number of orange post-it-pads sold in Store V = 120

Number of yellow post-it-pads sold in Store U = 380 (More) 
Number of yellow post-it-pads sold in Store V = 120 

Colour(s) of post-it-pads that Store U sold less than Store V = Orange (O)

(c)
Percentage increase in the number of blue post-it-pads sold by Store V from August to September
= ¹⁵₁₀₀ x 100%
= ³₂₀ x 100%
= 15%

Answer(s): (a) 380; (b) O; (c) 15%