How many words can a pen with half refill write?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

Can you write down eight eights so that they add up to one thousand?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

Decode below rebus
D
N
A
T
S , D

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

There are three boxes on a table. One of the box contains Gold and the other two are empty. A printed message contains in each box. One of the message is true and the other two are lies.

The first box says "The Gold is not here".

The Second box says "The Gold is not here".

The Third box says "The Gold is in the Second box".

Which box has the Gold?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?