Solution:

450

Explanation:
60 / 2(10+5) = ?
60 / 2(15) = ?
60 / 2 x 15 = ?
Using the BODMAS rule, we need to apply division first.
30 x 15 = ?
450 ..... The Answer

Solution:

10

Explanation:
Equation 1 + 9 + 11 = 1 can be derived from
One (o) + nine (n) + eleven (e) = one => 1

Similarly for equation,
12 + 11 + 9
Twelve (t) + eleven (e) + nine (n) => ten (10)

Solution:

Sansa has the siamese (conjoined) twin sister.

Solution:

Playing chess

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

Solution:

A cigar stuck in the wall

Solution:

Align the toothpicks to form TEN. Use one toothpick for each of the lines.

Solution:

Move and then pour all juice from second glass to fifth glass.

Solution:

In the picture you can find the green matchsticks. We have moved them from the bottom and placed them in the middle. It was a bit tricky but now you have your desired result.

Solution:

We now have a square of 3x3 size, 2 squares of 2x2 size and 5 squares of 1x1 size.

Solution:

Since each one of them gave one answer wrong, this means that each one of them gave two answers right.

Let us assume that Student A gave a wrong answer to the first question. This will mean that Student B also gave a wrong answer for the first. This will conclude that the rest of the two answers given by them are correct. However, the answers are different and thus it is not possible.

Thus both Student A and Student B must be right with the first question and the answer to the first is two.

If you keep applying the same logic, you will come to a conclusion that following are the correct answers:
Q1. Two
Q2. Three
Q3. Two

Solution:

Lucky days are here again.

Explanation:
Lucky + Day + s + R + H + Ear + Again (Flower represent lucky symbol)