When you add each of the numbers, you get the number 34.668. However, you have to remember to put the answer to the right number of significant figures. To do this, you have to look at the three numbers you added, and the answer must have the same number of decimal places as the addend with the lowest number of decimal places. In this case, the lowest number of decimal places is one (in the number 16.2), therefore; you have to round 34.688 to one decimal place, which would be 34.7 and just put that variable right back in front. So the final answer is 34.7m