PSLEThe pie charts show the number of each type of stationery in 2 stationery boxes, M and N. The total number of stationery in Box M is four times the total number of stationery in Box N.
- Find the percentage of rulers in Box M.
- What fraction of stationery in Box N is rulers?
- The number of rulers in Box M is 120. Find the number of rulers in Box N.
(a)
90°360° = 25% of stationery in Box M
Percentage of glues in Box M = 25%
Percentage of rulers in Box M
= 100% - 45% - 25%
= 30%
(b)
Percentage of rulers in Box N
= 100% - 65% - 25%
= 10%
Fraction of stationery in Box N that is rulers
= 10100
=
110 (c)
30% of stationery in Box M = 120
1% of stationery in Box M = 120 ÷ 30 = 4
100% of the stationery in Box M = 100 x 4 = 400
Number of stationery in Box N
= 400 ÷ 4
= 100
100% of stationery in Box N = 100
1% of stationery in Box M = 100 ÷ 100 = 1
10% of stationery in Box M = 10 x 1 = 10
Number of rulers in Box N = 10
Answer(s): (a) 30%; (b)
110; (c) 10