We randomly select 4 prime numbers without replacement from the first 17 prime numbers. What is the probability that the sum of the four selected numbers is odd? Express answer in common fraction.
I did this problem as
(1/17 * 1/16 * 1/15 * 1/14) * 9
I multiplied by I could form sum as odd.
Please correct me. I am not myself sure with the approach.
We select 5 numbers at random, with replacement, from the set of integers from 1 to 400 inclusive. What is the probability that the product of 5 numbers is even? Answer should be in common fraction.
I guessed my answer:
Please guide me in the above problems.