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?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

How can you take 2 from 5 and leave 4?

A and B have a certain number of chocolates with them. If B gives one chocolate to A, they will have an equal number of chocolates. But if A gives one chocolate to B, then A will be left with half the number of chocolates that B has.

Can you find out the number of chocolates they have right now?

Count the number of triangles in the given picture.

When 99 is considered higher than 100?

Which country gets ill every time?

There is so small cabin inside a deep forest.
All the forest burned out to worst possible but the inside of the cabin is still the same.
However all the person inside the cabin die.

How come ?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?