PSLE
School camp skirts were available in 4 colours: white, grey, silver and brown. At the camp, each students chose one skirt. The pie chart represents the students' choice of skirt colours. 40 students chose white skirts. The students' choice of skirt colours is also represented by the bar graph. The bar that shows the number of students who chose grey skirts has not been drawn. How many students chose grey skirts?

    
From the pie graph,
fraction of students who chose silver or brown
= ^90°_360°
= ¹₄

From the bar graph,
Number of students who chose silver = Number of students who chose brown = 50 

¹₄ of the pie chart = 50
⁴₄ of the pie chart = 4 x 50 = 200

Total number of students = 200

Number of students who chose grey skirts
= 200 - 50 - 50 - 40
= 60

Answer(s): 60