National Instruments Interview Question
Software Engineer / DevelopersCountry: India
Interview Type: Written Test
The question is how many person, that is why the result can be greater than 1. In term of the probability for one person to hit twice, it is always less than 1 : P^2 <= P <= 1.0
I think one person hitting ball is p^2(2*(1-p)*p+(1-p)*(1-p)) since no others must hit ball twice
The probability one person hit the stump twice is E(X) = P^2
- LinhHA05 July 24, 2013Assume that n people (n= 5) are n independent variables (the result from one does not influence result of the others) then the expected number of people who hit both time is
E(X1) + E(X2) + .. E(Xn) = n E(X) = n * P^2
Quick validation if P = 1, always hit, and all the people hit twice then there are 5 people hit
P = 0, always failed, non-of-them hit, then we expect 0 as the result