No. of ways of selecting none or more of 10 identical things is

The number of ways of selections one or more out of 7 given things is

Number of ways of selecting one or more things out of n dissimilar things are

Number of ways of selecting one or more things out of n dissimilar things are

Number of ways of selecting one or more things out of n dissimilar things are

The number of ways of selecting one or more things out of n dissimilar things is

Prove that the number of selections of n things from two sets of n identical things and n other distinct things is (n+2)2^(n-1)

If there are 5 alike pens, 6 alike pencils and 7 alike erasers, find the number of ways of selecting any number of (one or more) things out of them.

Number of ways of selecting r consecutive things out of n things