In a group of 40 people

Question

10 are healthy and every person of the remaining 30 has either high blood pressure, high level of cholesterol or both. If 15 have high blood pressure and 25 have high level of cholesterol.How many people have high blood pressure and a high level of cholesterol?

Answer 1

X is the number that have BOTH High blood pressure and High Cholesterol.

 

15 - x have only high Blood PRessure.

25-x have only high cholesteral

 

There are 30 of them afflicted with at least on of the issues.

 

So 30 = X+15-x+25-x 

   30 = 40 - x

 

  30 + x = 40

  x = 40-30 = 10

 

10 people have BOTH high cholesterol AND high blood pressure

15 people have only high cholesterol

5  people have only high blood pressure

10 are healthy

 

Venn Diagram is the model of choice