PSLE
Shops Y and Z sell highlighters of four colours. The bar graphs show the number of highlighters sold by each shop in January. The bar for the number blue highlighters sold by Shop Y has not been drawn.

1. Half of the highlighters sold by Shop Y were blue highlighters. How many blue highlighters did Shop Y sell?
2. Which colour(s) of highlighters did Shop Y sell less than Shop Z? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In February, Shop Z sold 25 less pink highlighters than the number of pink highlighters sold in January. What was the percentage increase in the number of pink highlighters sold by Shop Z from January to February?

(a)
Number of orange highlighters sold in Shop Y = 100
Number of pink highlighters sold in Shop Y = 160
Number of green highlighters sold in Shop Y = 80

Since blue highlighters sold in Shop Y is half of the highlighters sold by Shop Y, the total of pink highlighters, green highlighters and orange highlighters is equal to blue highlighters.

Number of blue highlighters sold in Shop Y
= 160 + 80 + 100
= 340

(b)
Number of orange highlighters sold in Shop Y = 100 (Less) 
Number of orange highlighters sold in Shop Z = 160

Number of pink highlighters sold in Shop Y = 160 (More)
Number of pink highlighters sold in Shop Z = 100

Number of green highlighters sold in Shop Y = 80 (Equal)
Number of green highlighters sold in Shop Z = 80

Number of blue highlighters sold in Shop Y = 340 (More) 
Number of blue highlighters sold in Shop Z = 160 

Colour(s) of highlighters that Shop Y sold less than Shop Z = Orange (O)

(c)
Percentage decrease in the number of pink highlighters sold by Shop Z from January to February
= ²⁵₁₀₀ x 100%
= ¹₄ x 100%
= 25%

Answer(s): (a) 340; (b) O; (c) 25%