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.

Q: In Mr. Olsen's mathematics class, 0.7 the students received A's and 0.2 received B's. What fraction of the students received either A's orB's?

A: 0.9
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Q: Sandy had 36 pennies and 31 nickels in her bank. Her dad borrowed20 nickels from Sandy. How many nickels does she have now?

A: 11.0
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Q: A bucket contains 3 gallons of water. If Derek adds 6.8 gallons more,how many gallons will there be in all?

A:
9.8
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