Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

There is a number which when you multiply by 3 and subtract 2 from the result, then the resulting number is the reverse of the actual number.

What is the smallest number that stands true on the statement?