You are given a math word problem and you are supposed to apply a single mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report final the numerical answer.
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Question: Brennan had 0.25 grams of pepper . Then he used 0.16 grams of the pepper to make some scrambled eggs . How much pepper does Brennan have ?

Answer: 0.09


Question: A restaurant served 6 cakes during lunch and 9 during dinner today . How many cakes were served today ?

Answer: 15


Question: Christine wandered 20 miles at 4 miles per hour . How long did Christine wander ?

Answer:
5