No, it isn't. You are told that "X horses can eat through Y bags of feed in Z days." That means that Y/X is the "number of bags of feed per horse" for Z days, not one day.The rate of eating for each horse is Y/X per day
[/quote]V similar horses would consume V(Y/X) of bags per day[/quote]
Not "per day"- "per Z days".
For exactly the reason I said. Since "X horses can eat through Y bags of feed in Z days." "X/Y" would be the amount of feed per horse for Z days, not for one day. V(Y/X) is the amount of feed for V horses for Z days, not for one day. The amount of feed for V horses per day would be [V(Y/X)]/Z= (VY)/(XZ).Therefore it would take U/V(Y/X) days
Now my teacher corrected this by putting (UX/VY)Z which I do not understand. Could someone explain this very clearly? With many thanks...