If eleven plus two equals one, what does nine plus five equal?

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?

Find the missing number in the series below

13 -21 34 -55 ? -144

In a school, 280 students studied chemistry, 254 students studied physics and 280 students studied biology.

97 students studied chemistry as well as physics, 138 students studied physics as well as biology and 152 students studied chemistry as well as biology.

73 students studied all the three branches.

Can you find out the total number of students?

I look at you, you look at me I raise my right, you raise your left. What am I?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

Can you divide the below-given shape into four equal and identical pieces?

We have two identical balls in terms of diameter and weight. However, one of them is solid and the other is hollow.

Without knocking the ball, can you find the solid ball?

I organized a small get together at my home.
In the party , i have a barrel with some whiskey in it.

Suddenly Guest 1 say 'I bet this barrel of whiskey is more than half full'.
'No, it's less than half full' Guest 2 replied.

I don't have any measuring instrument and without removing whiskey from it , how can i determine which of the guest is right ?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den