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

How can you write nineteen in a manner that if we take out one, it becomes twenty?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

If you say my name, I will no longer exist. What am I?

I have thought of a number that is made up by using all the ten digits just once. Here are a few clues for you to guess my number:

First digits is divisible by 1.
First two digits are divisible by 2.
First three digits are divisible by 3.
First four digits are divisible by 4.
First five digits are divisible by 5.
First six digits are divisible by 6.
First seven digits are divisible by 7.
First eight digits are divisible by 8.
First nine digits are divisible by 9.
The number is divisible by 10.

Can you find out the number ?

We can be boring,Or interesting.
We can be long,Or short.
We can have pictures,Or just words.
Many love us,But many also hate us.
What are we?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

Count the squares in the matchstick puzzle below?