Question

In how many ways can 3 boys and 4 girls be arranged in a row so that all the three boys are together.

Answer 1

4 girls and 3 boys are together can be considered as 1 unit (total 5) can be permuted in 5! ways and 3 boys together can be permuted in 3! ways. 

∴ Total number of ways = 5! 3! = 120 × 6 = 720 ways.