Question

The following pie diagram shows the percentage of persons according to blood group in a blood group checking camp. Answer the following questions:

1. Find the measure of the central angle for each blood group.
2. Find the total number of persons if there are 600 persons with blood group B.

Answer 1

a. Central Angle = `"Percentage of blood group"/100 xx 360`

O = `45/100 xx 360` = 162°

A = `20/100 xx 360` = 72°

B = `30/100 xx 360` = 108°

AB = `5/100 xx 360` = 18°

b. We are given that there are 600 persons with blood group B (which is 30% of the total).

Using the proportion formula:

Total Persons = `("Persons with Blood Group B" xx 100)/("Percentage of B")`

= `(600 xx 100)/30`

= 2000

So, the total number of persons in the camp is 2000.