GRE Math : How to find fractional percentages

Example Questions

Example Question #1 : How To Find Fractional Percentages

What percentage of a solution is blood if it contains ml blood and ml water?  Round to the nearest thousandth?

Explanation:

First, you must find the total amount of solution.  This is , or .

Now, the percentage of the solution that is blood can be represented:

, or

This is the same as %  Rounded, it is %

Example Question #2 : How To Find Fractional Percentages

What is the percentage increase of an account that began with a balance of  and increased to ?

Explanation:

Recall that the formula for percentage increase is: