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

What is common among 11, 69, and 88?

Why is Saturday stronger than Monday?

What happened when the wheel was invented?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Can you make four (4) nines (9) equal 100?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

What English word has three consecutive double letters?

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?