Two boats, traveling at 5 and 10 kms per hour, head directly towards each other. They begin at a distance of 20 kms from each other. How far apart are they (in kms) one minute before they collide?
Relative speed of two boats = 5 + 10 = 15 km/hr
In 60 minutes, they cover (together) = 15 km
In 1 minute, they will cover (together) = 15/60 km = 1/4
The correct option is B.