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?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Replace the question mark with the correct number below.

Move three sticks of the spiral below to form a square.

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

Decode this picture on T-Shirt and tell what it says ?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?