Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

What does this below rebus puzzle mean?

John needs to purchase 100 chocolates from three different shops and he has exactly 100 rupees to do that which he must spend entirely. He must buy at least 1 Chocolate from each shop.

The first shop is selling each chocolate at 5 paise, the second is selling at 1 rupee and the third is selling at 5 rupees.

How many chocolates should he buy from each shop?

Rearrange the letters in "new door" to make one word.

Manish and Manoj play 5 games of chess.
Both Manish and Manoj win the exact same number of games. There is no tie at all.

How?

Can you count the number of quadrilaterals in the picture below?

Identify the hidden meaning behind this picture?

Remove two matchsticks to make the below equation correct.

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?