Need help with a probability problem

[Klynn85]

Hi I was wondering if anyone could help me with this problem.

Only about 14% of senior citizens get the flu each year. However, about 24% of people under 65 years old get the flu each year. The general population consists of 12.5% senior citizens.

a) What is the probability that a person selected at random from the general population is a senior citizen who will get the flu this year?

b) What is the probability that a person selected at random from the general population is a person under age 65 who will get the flu this year?

I'm really stuck on this one so any help would be greatly appreciated.

 

[arthur ohlsten]

Assume the population consists of 1000 000 people

NUMBER OF SENIOR CITIZENS = 125,000
number of senior citizens with flu is 14.5% of 125,000 = 18,125
number of seniors without flu= 106,875

number of non seniors= 87.5% of 1000000= 875,000 people
non seniors with flu= 210,000
non seniors without flu=665,000

A) senior with flu= 18,125/1000000
senior with flu= .018125 or 1.81%

B) non senior with flu= 210,000/1000000
non senior with flu= .21 or 21%

please check the math. I have been making errors.
Arthur