Problem 96 medium

Confidence that feeds on itself

A player takes 100 penalty kicks. He scores the first and misses the second. From the third kick on, his probability of scoring equals the fraction of his previous kicks that he scored. For example, after 3 goals in 5 kicks he scores the sixth with probability .

What is the probability that he scores exactly 40 of the 100 kicks?

Answer

Fractions, decimals with at least 3 significant digits, and expressions such as sqrt(2)/2, e^-1 or pi/4.

Hints 0/2

h

Solution

s Shown after a correct answer. Revealing it first marks the problem as seen, not solved.