Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

What does below Rebus mean ?

esgg sgeg gegs gsge

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

How many times in a given day, minutes and hour clock comes in a straight line ?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?