Six identical coins are arranged in a row. Determine the number of ways in which 3 heads and 3 tails can appear.

Six identical coins are arranged in a row. The total number of ways in which the number of heads is equal to the number of tails is

A coin is tossed 5 times. Determine the number of ways in which 0 head (i.e. 0 head and 5 tails) can appear. Also find the number of ways in which 1 head (i.e. 1 head and 4 tails) can appear, and so on. Then complete the given table :

A bag contains 5 black and 6 red balls. Determine the number of ways in which 2 black and 3 red balls can be selected.

Six candidates are called for interview to fill four posts in an office. Assuming that each candidate is fit for each post. determine the number of ways in which : first and second posts can be filled.

Six candidates are called for interview to fill four posts in an office. Assuming that each candidate is fit for each post. determine the number of ways in which : all the four posts can be filled.

If n objects are arrange in a row, then the number of ways of selecting three of these objects so that no two of them are next to each other is

Six candidates are called for interview to fill four posts in an office. Assuming that each candidate is fit for each post. determine the number of ways in which : first three posts can be filled.

Find the number of ways in which n different beads can be arranged to form a necklace.

Find the number of ways in which 12 different beads can be arranged to form a necklace.

Determine variance and S.D. od the number of heads in three tosses of a coin.