If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

Why is the Hole below a Lock?

Find the missing number in the sequence below:

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

You’re out on the water and see a boat filled with people. You look away for a second and look back again, but this time you don’t see a single person on the boat. Why? Hint: The boat did not sink.

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

Why Aeroplane windows are round?

If,

Akriti = 631
Levis = 521
Sroti = 521
Aneel = 533
Then,
Sunil =?