The exact answer would be 31,750, which I got by simply adding together. Since it is an estimate, you would either estimate / round at the end to a rough 31,000 or 30,000 or you could round each fragment. You could do 16900 rounded to 17000 and 14850 to 15000 = 32000. Depending on your method of course would depend your answer but as you can see 30,000-32,000 are all logical estimates.
