Question

In a group of 40 people, 10 are healthy and every person the of the remaining 30 has either high bloodpressure, a high level of cholesterol or both.(a) if 15 have high blood pressure and 25 have high level of cholesterol, how many people have highblood pressure and a high level of cholesterol?

Answer 1

15 and 25
is the answer

Answer 2

Answer:

10

Explanation:

Let A and B represents the following events.

A : The person have high blood pressure.

B : The person have high level of cholesterol.

Total number of peoples = 40

Healthy persons = 10

Either high blood pressure, a high level of cholesterol or both = 30

It means $n(A\cup B)=30$

It is given that 15 have high blood pressure and 25 have high level of cholesterol. It means

$n(A)=15$

$n(B)=25$

We need to find how many people have highblood pressure and a high level of cholesterol i.e., $n(A\cap B)$

$n(A\cup B)=n(A)+n(B)-n(A\cap B)$

Substitute the given values in the above formula.

$30=15+25-n(A\cap B)$

$30=40-n(A\cap B)$

$n(A\cap B)=40-30$

$n(A\cap B)=10$

Therefore, 10 people have high blood pressure and a high level of cholesterol.