In how many ways can 4 boys and 3 girls be seated in a row if girls must sit together?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 720
When some people must sit together, they are first tied into one unit and arranged with the others; then the people inside the unit are arranged among themselves.
The 3 girls as one unit with the 4 boys make 5 units: \(5!=120\) arrangements
The 3 girls can change places inside their unit in \(3!=6\) ways
Total: \(120\times6=720\)