Name a key which is hardest to turn.

If,

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

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

What has no start, end, or centre?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What colour was the bear?

Can you solve the below tricky visual equation?

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?