Question

Five boys and five girls want to sit in a row .In how many ways can they sit such that no two boys sit together?

Answer 1

5 girls can sit in 5 places in 5! Ways. In between, beginning and ending, there are 6 places. 5 boys can sit any 5 of 6 places in p(6,5)=5! Ways. By fundamental principle this can be done in 5!*5! Ways.