Four fair coins are tossed once. Find the probability mass function, mean and variance for number of heads occurred.

Three fair coins are tossed simultaneously. Find the probability mass function for number of heads occurred.

Two fair coins are tossed simultaneously (equivalent to a fair coin is tossed twice). Find the probability mass function for number of heads occurred.

Two fair coins are tossed simultaneously Find the probability mass function for number of tails occurred

If a fair coin is tossed 8 times. Find the probability of at most five heads.

A fair coin is tossed 10 times. Find the probability of at most 6 heads .