You are provided with an arithmetic question. Your task is to compute the solution using the given arithmetic operations. The only arithmetic operators needed to answer the questions are'+'(addition) and'-'(subtraction). The answer should be correct to one decimal place.
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Question: Elizabeth went to the salon and had 0.3 inch of hair cut off. Then next day she went back and asked for another 0.5 inch to be cut off. How much hair did she have cut off in all?

Answer: 0.8

Question: There are 7.75 gallons of water in Becky's fish tank. If Becky adds 7.05 gallons more, how many gallons will there be in all?

Answer: 14.8

Question: Fred has 5 yellow balloons, Sam has 6 yellow balloons, and Mary has7 yellow balloons. The balloons cost 5 dollars. How many yellowballoons do they have in total?

Answer:
18.0