Answer:
Step-by-step explanation
But the question does not say exactly what should be solve for.
He would have 9/12 yards left over because you have to create a common denominator which would be 12. so for 5/6 you would multiply by 2 so you have 10/12. 1/4 you have to multiply by 3 so you get 3/12. and 2/3 you have to multiply by 4 so you get 8/12. then you add them 10/12+3/12+8/12 = 21/12 which simplifies to 1 9/12 and because he used 1 yard he is left with 9/12.
final answer: 9/12 yards
You just need to solve for when 
:
where 
is any integer. We only care about when 
, which happens for 
.
