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

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

With the help clues provided in the image, can you find the 5 digit key?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?