I have teeth but i don't bite. Who Am I ?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

A man dies of old age on his 25 birthday. How is this possible?

Replace the question mark with the correct number below.

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

Forwards I am heavy, backward I am not. What am I?

What do you answer even though it never asks you questions?