CAN I DO 1 JEE ADVANCED PROBLEM EVERY NIGHT?

When calculating the expected value (mean) of a random variable representing the absolute difference between counts of distinct items chosen from separate groups, one must account for all possible combinations using the combination formula C(n,r) = n!/(r!(n-r)!), rather than assuming only a few scenarios exist. The expected value is computed by multiplying each possible outcome by its probability (number of favorable combinations divided by total combinations) and summing these products.