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.

[EX Q]: Sam found 35 seashells on the beach, he gave Joan 18 of theseashells. How many seashells does he now have?
[EX A]: 17.0

[EX Q]: There were 9 red orchids and 3 white orchids in the vase. Sally cutsome red orchids from her flower garden. There are now 15 redorchids in the vase. How many red orchids did she cut?
[EX A]: 6.0

[EX Q]: Joan decided to sell all of her old books. She gathered up 33 books tosell. She sold 26 books in a yard sale. How many books does Joannow have?
[EX A]:
7.0