It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

During which month do people sleep the least?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

Can you write down eight eights so that they add up to one thousand?

What type of tree can I carry in my hand?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Can you decipher the two rows to find the hidden word?

A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log.

Can you calculate the weight of the entire wooden log?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

Replace the question mark with the correct number in below Picture: