A computer programm contains one error.in order to find the error, we split the program in to blocks and test 2 of them,selected at random.let X be the numer of errors in these blocks.compute E(x)...
If the E(X) = 1 then that means it has a 100% which is incorrect. Each
block has an equal probability to contain the error so 1/3 because you
choose 2/6.
