Math CentralQuandaries & Queries


Subject: common denominator
Who are you: Parent

what is the common denominator of 3/5, 2/7 and 4/8?

Hello there.

There are many common denominators that you can use. The easiest way to find a common denominator is to multiply the denominators together. In your question, that would be 5 x 7 x 8 = 280. That's not the
lowest common denominator though. This question is likely trying to show you that you should reduce your fractions as much as possible before trying to find a common denominator. What is 4/8 equal to? it is 1/2. So replace it and then try to find a common denominator of 3/5, 2/7 and 1/2. Then you don't have to deal with such large numbers as 280.

Hope this helps,
Stephen La Rocque.

About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS