People make me, save me, change me, raise me. What am I?

Can you solve the below rebus?

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?

Can you find out the number that should replace the question mark with a valid reason?

81 x 9 = 801. What must you do to make the this equation true?

A man escapes from jail using help from his girlfriend. The investigators suspect four girls of being the man's girlfriend.

Out of those four girls, one is his girlfriend who is lying. Two of the girls are completely innocent and are speaking the truth. One of the girls is the man's sister who is helping the girlfriend lie. Following are the statements from all four of them:

Ariana: "Myrna is his girlfriend."
Jane: "Angelina is lying."
Angelina: "Ariana is lying."
Myrna: "Jane is not his sister."

Can you find out who is the man's sister among them?

Can you Find and name the hidden bird in the picture below ?

What has many keys but can’t open a single lock?

Name a key which is hardest to turn.

What can go up a chimney down, but can’t go down a chimney up?