PSLE
School camp t-shirts were available in 4 colours: green, purple, brown and blue. At the camp, each pupils chose one t-shirt. The pie chart represents the pupils' choice of t-shirt colours. 40 pupils chose blue t-shirts. The pupils' choice of t-shirt colours is also represented by the bar graph. The bar that shows the number of pupils who chose green t-shirts has not been drawn. How many pupils chose green t-shirts?

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

From the bar graph,
Number of pupils who chose brown = Number of pupils who chose purple = 60 

¹₄ of the pie chart = 60
⁴₄ of the pie chart = 4 x 60 = 240

Total number of pupils = 240

Number of pupils who chose green t-shirts
= 240 - 60 - 60 - 40
= 80

Answer(s): 80