[Solved] A collective farm was due to deliver its quota of grain to the state authorities. The management of the Kolkhoz decided the trucks should arrive in the city at exactly 11:00 A.M. If the trucks traveled at 30 miles per hour they would reach the city at ten, an hour early; at 20 miles an hour they would arrive at noon, an hour late. How far is the Kolkhoz from the city, and how fast should the trucks travel to arrive at 11:00 A.M.?

This riddle has been around for some time on internet platforms such as Instagram, Facebook, and WhatsApp, and many people still argue over what the answer might be, as there are many possibilities. The correct answer is Kolkhoz is 120 miles away from the city and the truck should travel at 24 miles an hour. At 30 miles per hour a truck travels a mile in 2 minutes; at 20 miles per hour, in 3 minutes. At the latter speed the truck is 1 minute slower per mile. To lose 2 hours, or 120 minutes, takes 120 miles, which is how far the Kolhoz is from the city. At 30 mph, the truck would cover 120 miles in 4 hours. The trip is to take 1 hour longer, or to arrive at 11:00 A.M., and calls for a speed of 24 (120/5) miles per hour.