Using the rules for significant figures, what do you get when you add 24.545 and 307.3?
When you add 24.545+307.3= 331.845
You will go with the number with the smallest number, which is 307.3.
So answer will be 331.8
the correct answer is not what he said i just took the test and the correct answer is 331.8 i promise its correct for plato users!! if it isnt please dm me and tell me what is!! good luck!