Question Details

Question No: 46

Let S be the set of permutations of the sequence 1,2,3,4,5 for which the first term is not 1. A permutation is chosen randomly from S. The probability that the second term is 2, in lowest terms, is a/b. What is a+b?

Answer must be a floating-point or integer value and precision error less than 10^-6 is allowed.