Riddle: A nonstop train leaves Moscow for Leningrad at 60 mph. Another nonstop train leaves Leningrad for Moscow at 40 mph. How far apart are the trains 1 hour before they pass each other?
Answer: 100 miles (60+40)
Riddle: One fourth of the population of a newly discovered planet have 4 legs. The rest have two legs. There are 60 legs total. How big is the population of the newly discovered planet?
Answer: 24.
One fourth of the population of a newly discovered planet have 4 legs. The rest have two legs. There are 60 legs total. How big is the population of the newly discovered planet? Riddle Meme.
Riddle: There is a creature which could double its size every day. So, if the creature is put in a tank then it will fill the tank in 10 days. How many days would it take for the creature to fill 1/2 and 1/4 of the tank?
Answer: 9 days to fill 1/2 and 8 days to fill 1/4 of the tank.  If the creature fills the tank in 10 days and it doubles every day, on the ninth day it would fill 1/2 the tank. Thus on the 8th day it will fill 1/4 of tank.
Riddle: How can you measure nine minutes with have two hourglasses, one four minute and one seven minute?
Answer: Turn over both hourglasses at once. When the four-minute hourglass runs out, turn it over. When the seven-minute hourglass runs out, turn it over. When the four-minute timer runs out this time (eight minutes have elapsed), the seven-minute hourglass has been running for one minute. Now turn over the seven minute timer back over. When the timer runs out, nine minutes have elapsed.
Riddle: Three point one four, one five nine two six five, three five eight nine... What am I?
Answer: Pi - π.
Three point one four, one five nine two six five, three five eight nine... What am I? Riddle Meme.
Riddle: Place three matches on a table. Tell a friend to add two more matches to make eight. How can this be done?
Answer: Add two matches to make a roman numeral eight.
Riddle: A boy has as many sisters as brothers, but each sister has only half as many sisters as brothers. How many brothers and sisters are there in the family?
Answer: Four brothers and three sisters.
Riddle: A 300 ft. train is traveling 300 ft. per minute must travel through a 300 ft. long tunnel. How long will it take the train to travel through the tunnel?
Answer: Two minutes. It takes the front of the train one minute and the rest of the train will take two minutes to clear the tunnel.
Riddle: If two's company and three's a crowd, what are four and five?
Answer: Four and five is nine.
Riddle: What is significant about 3661 seconds past midnight on 1st January 2001?
Answer: The time and date will be 01:01:01 on 01/01/01.