12 lb 8 oz + 17 lb 8 oz
a-30 lb
b-29 1/2 lb
c-29 lb

So what you do is you first add the 12 and 17 and end with 29 pounds. 16 ounces make a pound, so since 8+8 is 16 that then makes it one pound. add those two together and you end up with 30. so the answer is A