Question 19.

The difference in the time take to traverse the same distance ′d′ at two different speeds is 35 minutes.

Equating this: $\frac{d}8$ − $\frac{d}{15}$ = $\frac{35}{60}$

On solving, we obtain d=10kms Let x kmph be the speed at which Amal needs to travel to reach the office in 50 minutes; then

$\frac{10}{x}=\frac{50}{60}$ or x = 12 kmph

​Hence, Option A is the correct answer.