Why do we preferably have round manhole covers and not square ones?

Our product and our sum always give the same answer. Who are we?

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

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Solve the maths equation in the picture below by placing the numbers 1 through 9 into the boxes so that all the 3 equations are correct.

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?

Find the next number in the following series:
6, 14, 26, 98, __?

What does Alexander the Great and Winnie the Pooh have in common?

Which Burger Is Different in below image?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?