# Help in solving a question

#### Aleem

##### New Member
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

#### CE479

##### New Member
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?

#### hlsmith

##### Less is more. Stay pure. Stay poor.
Look up Bayes Theorem and see what you think.

#### Maryam2008

##### New Member
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