Question

To draw a pie chart, we need to represent each part of the data as a proportion of 360, because there are 360 degrees in a circle. For example, if 55 out of 270 vehicles are vans, we will represent this on the circle as a segment with an angle of: $\frac{55}{27}\times 360=73$ degrees.
The pie chart below shows the percentages of blood types for a group of 200 people.

a) How many people, in this group, have blood type AB?
b) How many people, in this group, do not have blood type O?
c) How many people, in this group, have blood types A or B?

Answer 1

a) $19\%\times 200=\frac{19\times 200}{100}$ = 38 people
b) $(100\%-40\%)\times 200=\frac{60\times 200}{100}$ = 120 people
c) $(16\%+25\%)\times 200=\frac{41\times 200}{100}$ = 8 people