Can you fill the blank with the correct number?

6 30 870 756030 _____

Can you solve the maths in the below-given picture equation?

A Detective reviewed the information they had on the case so far.

A lady named 'Caterina' was found shot and they already had a list of suspects - Ankit, Tarun, Harish, Manoj and Manish.
The killer is a fan of challenges him by leaving notes ad various places.
* The first was found in a toilet room.
* The second was found in an art room.
* The third was in a restroom.
* the fourth in an underwater room.
* The fifth at the no-smoking room.

All of the notes read the same thing, 'The clues are where you find the notes.' Yet, nothing was found at any place the notes were.
Detective the genius, immediately solved the case.
Who was the killer?

81 x 9 = 801. What must you do to make the this equation true?

If two's company, and three's a crowd, then whats four and five ?

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

What does a man do only once in his lifetime, but women do once a year after they are 29?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

What has 88 keys?