What Adam and Eve do not have but the rest of the people have?

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?

What does this rebus photo means?

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

How can you make number one disappear by adding something to it?

Which famous Hollywood movie name is hidden in the below rebus?

Count the number of triangles in the below picture?

You bought me for dinner but never eat me. What am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

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 ?