Answer:
There would only be 1/10 of the box left.
Explanation:
In order to find this, subtract the two amounts eaten from 1 whole box.
1 - 3/10 - 3/5. = Leftover
Now give them all common denominators and perform the indicated operations.
10/10 - 3/10 - 6/10 = Leftover
1/10 = Leftover.