In how many ways 4 boys and 3 girls can be seated in a row so that they are alternate?
Trick: Since there is one more boy, the arrangement must be:
B G B G B G B
Arrange 4 boys = 4! = 24 ways
Arrange 3 girls = 3! = 6 ways
Total ways = 4! × 3!
= 24 × 6
= 144
Answer: 144 ways