George weeded 2/5 of the garden and Tiffany weeded some, too when they were finished, 4/15 of the garden still needed to be weeded. What fraction of the garden did Tiffany weed?

1 Answer
Jan 13, 2017

Tiffany weeded 5/15 of the garden.
5/15 is equivalent to 1/3.

Explanation:

George weeds 2/5 of the garden and 4/15 remains unweeded. It is difficult to compare fractions with different denominators. So it seems best to express 2/5 as an equivalent fraction like this: 2/5 = 2/5 . 3/3 = (2 . 3)/( 5. 3 )= 6/15

We can now add the various bits:

Tiffany's bit + George's bit + unweeded bit = The whole garden .
Tiffany's bit+ 6/15 + 4/15 = 15/15

Tiffany's bit + 10/15 = 15/15

So Tiffany's bit = 5/15
You can simplify this to 1/3 by cancelling out the common factor 5.