How many times in a given day, minutes and hour clock comes in a straight line ?

A bridge is about to collapse. There are four people P, Q, R and S on one of the sides. Before the bridge collapses, they want to cross it. Now since the bridge is too weak, it can only stand the weight of two people at a time. Also, it is night time and nothing is visible. They have just one torch with them.

Now P takes one minute to cross the bridge, Q takes two minutes to cross, R takes five minutes to cross and S takes ten minutes to cross.

The bridge will collapse in seventeen minutes. How will they be able to cross the bridge before it collapses?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

I have some blue and red sock in my drawer. I have a total of 4 socks. I pick 2 socks and the chance that I get a pair of red socks is 1/2.

What is the chance of picking a pair of blue socks?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

How many times can you subtract the number two from the number fifty?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

How many letters are in the alphabet?

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?