Solution:

10 percent of student study all four subjects.

Solution:

That person in the picture is the son of the man holding the picture.

Solution:

The two statements have given it out. If you read carefully, you will easily be able to deduce the answer.

We know that everybody is wearing a different color than their names. Now let us begin with the man who noticed the first i.e. Mr. Grey. He is wearing either Pink or Orange. But in the second statement, we already know that the person who is wearing Pink is somebody else. Thus Mr. Grey must be wearing a Orange shirt.

Mr. Pink cannot wear Pink shirt and Orange shirt has already been taken, thus he must be wearing a Grey shirt.

This leaves only one choice for Mr. Orange and he must be wearing a Pink shirt.

Solution:

Generation Gap

Solution:

This is absolutely possible. It happened because only three people went for fishing that day: The son, his father and his grandfather.

Solution:

It is perfectly feasible. The forty elephants had forty foreheads.

Solution:

Cry over spilt milk.

Solution:

After five minutes, the second friend turned around to see if anyone was there or not. At this moment, he was stabbed on back by his friend.

Solution:

I am a compass.

Because I am a compass and I help people navigate all around the world.

Solution:

Augustus and Joshua play all the three sports. Stacy plays none.

This is when we have assumed that girls do not play football at all. If by any means, the school has a girl's football league, all we know is that one of the three play no sports at all and the others play all the three.