PSLE
The pie charts show the number of each type of stationery in 2 stationery boxes, Y and Z. The total number of stationery in Box Y is four times the total number of stationery in Box Z.

1. Find the percentage of post-it pads in Box Y.
2. What fraction of stationery in Box Z is post-it pads?
3. The number of post-it pads in Box Y is 80. Find the number of post-it pads in Box Z.

(a)
^90°_360° = 25% of stationery in Box Y

Percentage of glues in Box Y = 25%

Percentage of post-it pads in Box Y
= 100% - 55% - 25%
= 20%

(b)
Percentage of post-it pads in Box Z
= 100% - 60% - 25%
= 15%

Fraction of stationery in Box Z that is post-it pads
= ³₂₀

(c)
20% of stationery in Box Y = 80
1% of stationery in Box Y = 80 ÷ 20 = 4 
100% of the stationery in Box Y = 100 x 4 = 400

Number of stationery in Box Z
= 400 ÷ 4
= 100

100% of stationery in Box Z = 100
1% of stationery in Box Y = 100 ÷ 100 = 1
15% of stationery in Box Y = 15 x 1 = 15  

Number of post-it pads in Box Z = 15

Answer(s): (a) 20%; (b) ³₂₀; (c) 15