Question

I need help:

Sarah has red, green and blue t-shirts.

2/5 of all t shirts are red

1/3 of all t shirts are green

What fraction of all t shirts are blue?

Answer 1

Here is how I would do it,

6/15+5/15 = 11/15

15/15 - 11/15 = 4/15. So the answer is 4/15.

Answer 2

4/15

Explanation:

Add the fractions for the red and green shirts

2/5 + 1/3

Get a common denominator which would be 15

2/5 *3/3 = 6/15

1/3 *5/5 = 5/15

6/15+5/15 = 11/15

The total has to equal 1 or 15/15

Subtract the red and green, which would leave blue

15/15 - 11/15 = 4/15

blue shirts are 4/15 of the total