Ubi made a banana cream pie. his brother at 1/3 of the pie and his sister ate 2/5 of the pie. how much less did his brother eat than his sister?

His brother ate 1/15 less than his sister did.

1. Find the lowest common factor between 3 and 5 which is 15

2. Multiply the top number (numerator) by whatever it took to get 15 on the bottom number

3. Then do the same for the second fraction

4. Now subtract.

If this doesn't make sense, leave a comment and I'll try to rephrase it.