Arithmetic Ability
 Probability

81 / 132

Q.

If x is chosen at random from the set {1,2,3,4} and y is to be chosen at random from the set {5,6,7}, what is the probability that xy will be even?

View Answer

Correct choice: B

Explanation:

S ={(1,5),(1,6),(1,7),(2,5),(2,6),(2,7),(3,5),(3,6),(3,7),(4,5),(4,6),(4,7)} Total element n(S)=12 xy will be even when even x or y or both will be even. Events of x, y being even is E. E ={(1,6),(2,5),(2,6),(2,7),(3,6),(4,5),(4,6),(4,7)} n(E) = 8 P(E)=n(E)n(S)=812 = 4/3
81 / 132