Using Only Five 5's and any mathematical operator make sum as 37

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

Find out the missing number in the picture attached:

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

John can eat 27 chocolates in an hour, Jacob can eat 2 chocolates in 10 minutes, and Jolly can eat 7 chocolates in 20 minutes. How long will it take them to share and eat a box of 120 chocolates whilst playing Chess?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.