The operations and symbols that are allowed are: the four arithmetic operations (+,x,-,/), concatenation (44 is ok and uses up two 4's), decimal points (using 4.4 is ok), powers (using 4^{4} is ok), square roots, factorials (using 4! is ok), and overbars for indicating repeating digits (e.g., writing .4 with an overbar would be a way of expressing 4/9). Ordinary use of parentheses are allowed. No digits other than 4 are allowed.

This problem is sometimes called the *four fours* problem. It was popularized by Martin Gardner, among others.

So... Take out your pen and paper... find all the possibilities from 1 to 100. Write your answers in the comment box.

Can it be

ReplyDelete(4/.4)*(4/.4) ??

yes, such type of solutions are also accepted.

ReplyDelete