Solution:

The answer is D.

Since all the patters appear twice in the given picture, the answer will be the option which does not have similar faces.

Solution:

The required digit is 0.
If you add up all the digits in any diagonal, you will find the sum to be 25.

Solution:

Popular Illusion - It can be seen as
1. Vase painted with white
Or
2. Two faces facing each other painted in black.

Solution:

There are twenty-four triangles in the given picture.

Solution:

The rabbit is present in the left tusk of the elephant.

Solution:

The number missing on the left is 8 and the one on right is 7.

Explanation:
The pattern:
The number in the center of triangle is the square root of the sum of the numbers sitting outside on the corners.

Thus,
10 + 22 + 4 = 36
Square Root of 36 = 6

In the same manner:

10 + 42 + 12 = 64
Square Root of 64 = 8

12 + 22 + 15 = 49
Square Root of 49 = 7

Solution:

It can be achieved as it is shown in the figure.

Solution:

The correct choice will be the option 'd'.

In each succeeding row, the previous column is reversed and the lowest digits are omitted.

Solution:

We have provided you with one of the possible solutions. However, there can be three more solutions to this problem.

Solution:

The missing letter on left is P and the missing letter on the right is C. The word starts from the missing letter C and forms the word champion.