Before Mount Everest was discovered, what was the highest mountain in the world?

This was asked in an interview with Coa-Cola.

The interviewer has given me 100 marbles(50 white and 50 black) and two empty boxes.
He then told me that he will leave the room and i need to place all the marbles in two boxes.

And When he come back, he will draw a marble from any of the two box and if the marble is white I will be hired.

Also
* No box can be empty.
* All 100 marbles must be placed in one of the two boxes.

So what should I have done?

What has one eye, but can’t see?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

Can you find the ages of a son, father and grandfather based on the following facts?
The sum of the ages of grandfather, father and son is 140 years.
The age of the son in months is the same as the grandfather in years.
The age of the son in days is the same as the father in weeks.

John was running from 40 thieves. John has got 3 gold boxes which weigh as 4kg, 2kg, and 1kg respectively. A witty man asked John to stay with him for seven days in exchange for 1kg gold per day. John needs to stay there for seven days and also do not want to give the witty man any advance. How can John pay for his seven days stay?

The dirtier I get, the whiter I look. Who am I?

It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

How many Watermelons are there in the below picture?