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

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

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?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

The Federal bank of London is abducted by the robbers. The head of the robbers asked the cashier to empty their money vault to them and when suddenly cashier got a call from her father. To avoid any suspicion, the robber asked the cashier to pick the call and reply her father in the shortest manner possible.

The cashier told her father "Is there an emergency father, Call me when you are free and I will help you in your furnishing" and then the cashier hung up the phone.

After 10 minutes, police arrived at the crime scene.

How did the police know about the robbery?

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

What number divided by 4 is the same as that number minus 4?

By what process could you make a 'Tea-Table' into food?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

If an electric train is travelling south, then which way is the smoke going?