Question 610248
The question is not clear. Did he give 2/6(1/3) of a cup or 2/6 of what he had.
The 6/10 is even more vague.  Why isn't 2/6 expressed in reduced form as 1/3 and the same with 6/10 for 3/5 and 12/14 as 6/7. 
Assuming 3/5 cup and 1/3 cup
6/7-1/3+3/5

 90/105-35/105+63/105 

 118/105
1 13/105