# Thread: Help in solving a question

1. ## Help in solving a question

Hello everyone,

I am working on some exercise questions from probability. I am stuck at this question. Can somebody help me to solve this. I would really appreciate.

In a certain country, 35 percent of people are known to have diabetes. It is also known that people over 65 year of age have 22 percent more chances to have diabetes. What is the probability that a person is diabetic knowing that he is below 65?

I have done some work but don't know if it is correct or not.
P(B) = 0.35 -- People having diabetes
P(A|B) = ? -- People with age less than 65 having diabetes
P(A n B) = 0.22 – People with over 65 age and having diabetes
P(A|B) = 0.22/.35 = 0.62

2. ## Re: Help in solving a question

Hmm- seems it should not be that hard, but I am not sure!
If the risk of having diabetes over age 65 is 22 percent more, then the risk under 65 should be the reciprocal? (1/1.22)
Therefore 0.35 * (1/1.22)= 0.29?

3. ## Re: Help in solving a question

Look up Bayes Theorem and see what you think.

4. ## Re: Help in solving a question

Originally Posted by Aleem
Hello everyone,

I am working on some exercise questions from probability. I am stuck at this question. Can somebody help me to solve this. I would really appreciate.

In a certain country, 35 percent of people are known to have diabetes. It is also known that people over 65 year of age have 22 percent more chances to have diabetes. What is the probability that a person is diabetic knowing that he is below 65?

I have done some work but don't know if it is correct or not.
P(B) = 0.35 -- People having diabetes
P(A|B) = ? -- People with age less than 65 having diabetes
P(A n B) = 0.22 – People with over 65 age and having diabetes
P(A|B) = 0.22/.35 = 0.62

Salam Aleem
This is what I think from the question that
Total population who has DM is 35%
Population greater than 65 who has DM is 22%
So population who is less than 65 who has DM is 35-22= 13%

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