Take away the whole and some still remain. What is it?

In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

In the picture given below, can you find out which digit will take place of the question mark?

Next Number in the Series,

5, 16, 49, 104, ?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

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?

Find the smallest sentence with all the English alphabet.

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

what does the below math rebus puzzle mean?