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?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

If two's company, and three's a crowd, then whats four and five ?

There’s a girl who has a large family. She has an equal amount of brothers and sisters, but each brother only has half as many brothers and sisters. What’s the correct amount of brothers and sisters?

Replace all '*' with digits 1, 2, 3, 4, 5 and 6 to make below statement true.

* *
x *
=====
* * *

I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well

what am I looking for?

This is the oldest riddle that I have heard.

Once there was a man who was travelling with a Tiger, goat and grass.
He needs to cross a river that can carry a maximum of two i.e. Man + one of Tiger goat or grass. But the problem is "If he takes the lion with him, the goat will eat grass and if he takes grass with him, the lion will eat the goat".

How can he ensure the safe delivery of all three?