What am I?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

John is found dead in a bare field. Nobody killed John,
John did not commit suicide.

Inspector Jacob found a bag just a few meters away from John which could save his life. What was in the bag?

John was writing his first book. After saving the document, he locked his laptop with a password and mentioned some phrases for the hint box.

A friend of his tried opening his laptop but found out that it was password protected. Following is the hint that appeared.
1 mobile 3 books 2 roars 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches.

Can you help him in cracking the password?

O_er_t_o_

Complete the missing letters of the given word.

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

What has 13 hearts but no other organs?

Can you decipher the below rebus?

PBLUESAISNUERSES