Question

Let the 9 different letters

A, B, C.... I Ī {1, 2, 3,....9} then the probability that product (A – 1)(B – 1)..... (I – 9) is even number will be-

• A. $\frac { 1 } { 2 }$
• B. $\frac { 1 } { 4 }$
• C. 1
• D. 0

Answer 1

Answer: (C)

1

Answer 2

Given set of numbers is {1, 2, ......, 9} in which 4 are even and 5 are odd, so in the given product it is not possible to arrange to substract only even number from odd number, there must be atleast one factor involving substraction of an odd number from another odd number. So at least one of the factor is even. Hence product is always even.\ Required probability = 1