Solution:

797

Explanation:
797 is a prime number
79 is a prime number
7 is a prime number

Solution:

prinka is 10, in a system that awards five for each vowel.

Solution:

fIvE thOUsAnd(5000)

Solution:

Playing chess

Game needs two players so Brother-8 is playing chess with Brother-2

Solution:

The wise man told them to switch the horses and then race. In this manner, both of them will be willing to race as fast as they can to prove that the other horse (his own horse) is slow.

Solution:

The answer is 'R'

It represents the gear stick. The number 1-5 represents gears and the last one thus should be reverse i.e. R.

Solution:

13 + 11 + 6 = 30

Explanation
The trick is that you just need to rotate '9' to form '6'.

Solution:

The node can be connected as shown.

Solution:

7

Explanation:
8th is bald man head, check the video below.

Solution:

The stranger said that he thought the room was his. If so, he must have had the keys to the room and thus he must not have knocked.

Solution:

Four

three placed flat on the table in a triangle(touching each other) and put the fourth one on top of them in the middle.