First let's write the equations of cost for each company, for the first company we have:

Where "c" is the cost and "s" is the tons of sugar.
For the second company, we have

Therefore if we want to know when the tons and the cost will be equal, we must solve the system of equations:

Look that we have two equations for c, then we say that

And solve it for "s"

Therefore for 16 tons of sugar the cost will be the same, now we put 16 on one of the equations to find it

Therefore for 16 tons of sugar, the cost will be $3612 for both companies.