Instructions: 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.
Input: Sara has 31 red and 15 green balloons. Sandy has 24 red balloons.How many red balloons do they have in total?
Output:
55.0