Definition: 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: Sam has 86 yellow and 20 green marbles. Joan took 25 of Sam'syellow marbles. How many yellow marbles does Sam now have?

61.0