Question

Three boys and four girls stand in queue for an interview. The probability that they stand in alternate positions is:

• A. (1/35)
• B. (3/35)
• C. (1/49)
• D. (3/49)
• E. None of these

Answer 1

The correct option is A

(1/35)

Total number of possible arrangements for 3 boys and 4 girls in a queue = 7!

When they occupy alternate positions, the arrangement would be like:

G B G B G B G

Thus, total number of possible arrangements for girls = 4!

Total number of possible arrangements for boys = 3!

Required probability = $\frac{4!3!}{7!}$ = $\frac{1}{35}$