If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What has hands, but can’t clap?

I am sure no one can have two things for dinner. what are they?

In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?

What is the next number in this series?

4,12,84,3612....

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?