Out of four images which one is the odd one out?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

There was a strange boy who was born before his father. How can this be possible?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

Count the Triangle in the figure given below:

John is pretty weird. He likes toffees but hates chocolates. He loves books but never reads. He likes to build his troops in an online game but does not proceed with the war. He likes to go swimming but is afraid of water.

Seeking this behaviour, can you tell whether he likes balloons and parties?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

What runs around the whole yard without moving?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?