Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

The host of a game show, offers the guest a choice of three doors. Behind one is a expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Look at the picture and find out which square is not linked with any of the other squares.

Why is it very easy to weigh a fish?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

What does this rebus mean?

O
N
C
E
TIME

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

What demands an answer, but asks no questions