Question

Three different numbers are selected at random from the set A=(1,2,3,....,10). The probability that the product of two of the numbers is equal to the third is A. 3 4 B. 1 40 C. 1 8 D. 39 40 Select the correct answer from above options

Answer 1

Correct Answer - B Out of 10 numbers, three numbers can be chosen in .10C3 ways. ∴ Total number of elementary events =.10C3 The product of two numbers, out of the chosen numbers, will be equal to the third number if the numbers are chosen in one of the following ways : (2,3, 6), (2, 4, 8), (2, 5, 10) ∴ Favourable number of elementary events =3 Hence, required probability = 3 .10C3 = 1 40