Can you find out the missing number in the grid?

What does this Rebus Picture mean?

What is next number in the pattern below:

131 517 192 123 ?

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

Solve the following series:
AZ, GT, MN, __, YB

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

You need to remove two matchsticks to make the below equation true. Can you do it ?

A wealthy man lives alone in a small cottage. Being partially handicapped he had everything delivered to his cottage. The mailman was delivering a letter one Thursday when he noticed that the front door was ajar. Through the opening he could see the man's body lying in a pool of dried blood. When a police officer arrived he surveyed the scene. On the porch were two bottles of warm milk, Monday's newspaper, a catalog, flyers, and unopened mail. The police officer suspects it was foul play. Who does he suspect and why?

While house hunting in London, I came across a very good leasehold property Discussing the lease the landlady told me:

'The property was originally on a 99 years lease and two-thirds of the time passed is equal to four-fifths of the time to come. Now work it out for yourself and see how many years are to go!

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()