Probability Mcqs
Q. 10 books are placed at random in a shelf. The probability that a pair of books will always be together is_________?
a. 1/10
b. 9/10
c. 1/5
d. 3/10
10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5
