Hard Riddles

Hard riddles with answers are a true test of your brain power, reasoning and comprehension. You are sure to find these tough difficult riddles both challenging and puzzling. While these hard riddles and answers may drive you a little crazy sometimes, they may surprise you in the way they force you think out of the box.

Mail Valuable Object

Suppose you want to send in the mail a valuable object to a friend. You have a box that is large enough to contain the object and the box can be fitted with multiple locks.

Both of you also have several locks and their corresponding keys. However, your friend does not have the keys to any of your locks. If you send a key in an unlocked box, there is a danger of theft.

How can you send the object securely to your friend?

Riddle Answer

Two Trains and a Fly

Two trains travel toward each other on the same track, beginning 100 miles apart. One train travels at 40 mph (miles per hour); the other travels at 60 mph.

A fly starts flight at the same location as the faster train, flying at a speed of 90 mph. When it reaches the slower train, it turns around, flying the other direction at the same speed. When it reaches the faster train again, it turns around, and so on. When the trains meet, how far will the fly have flown?

Riddle Answer