Question

Two integers are selected at random from integers 1 through 11. If the sum is even, find the probability that both the numbers are odd. A. 3 5 B. 2 5 C. 1 5 D. 4 5 Select the correct answer from above options

Answer 1

Correct Answer - A Out of integers from 1 to 11, there are 5 even integers and 6 odd integers. Consider the following events : A= Both the numbers chosen are odd, B=The sum of the numbers chosen is even. ∴ Required probability =P(A/B) =Probability that the two numbers chosen are odd if it is given that the sum of the sum of the numbers chosen is even. = .5C2 .5C2+.6C2 = 3 5