There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

If I put in one bird per cage, I have one bird too many. If I put in two bird per cage, I have one cage too many. How many cages and birds do I have?

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?

What is so fragile that saying its name breaks it?

In the four images below, can you find the odd one out?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

Why is 6 afraid of 7?