From Goa to Mumbai there are 5 flights . In how many ways can Suresh go from Goa to Mumbai and return by a different flight ?

There are 6 trains running between Indore and Bhopal . In how many ways can a man go from Indore to Bhopal and return by a different train ?

There are 10 buses running between two towns X and Y. In how many ways can a mango from X to Y and return by a different bus ?

There are 10 buses running between Delhi and Agra. In how many ways can a man go from Delhi to Agra and return by a different bus?

From Panipat to Delhi there are 10 buses. In how may ways can Pooja go from Delhi to Panipat and return on a same day by a different bus after attending a function ?

From Panipat to Delhi there are 10 buses. In how may ways can Pooja go from Delhi to Panipat and return on a same day by a different bus after attending a function ?

There are 6 trains running between New Delhi and Darbhanga. In how many ways can a man go from New Delhi to Darbhanga and return by a different trains?

There are 6 trains running between New Delhi and Darbhanga. In how many ways can a man go from New Delhi to Darbhanga and return by a different trains?

There are 15 buses running between Lucknow and Kanpur. In how many ways can a man go to Kanpur and return by a different bus?

In how many ways can 2 doors be selected from 3 doors ?

In how many ways can one choose 5 books from 10 different books?