This was a problem used in the preparation of the USA Math Olympiad in 2016 by Kettering University. This is an easy question that might be too easy to be a worthy problem used in a Math Olympiad. It may however function very well as an on the spot interview question where you have to … Read more

## How many degrees are there between the hour and minute hands when it’s 3:15 PM?

People have given me answers to this one ranging from to (and many answers in between). The big hand is on the three; the little hand is one-quarter of the way between the three and the four. The answer must be one-quarter of one-twelfth of That is, one-quarter of That is, (or radians if you … Read more

## What is ?

Well, if the answer were zero they wouldn’t be asking it. Just multiply by the ratio of its conjugate to itself and divide numerator and denominator by :

## Differentiate with respect to

This problem is a popular interview question at places that require a quantitative mindset. Finding derivatives is a purely mechanical process which doesn’t require any creativity and once you’re used to parsing expressions and applying the rules, you can determine the derivative of any explicit expression you are given.

There are two ways … Read more

## Divisibility of a number by recursion

Does there exist a number of the form 444…4443 (all 4’s and at the end a 3) that is divisible by 13? If yes, give a number of that form that is divisible by 13; if not, then prove that there is not such a number.

This problem was asked on the second round … Read more