The task is to generate the correct answer for a given math problem.
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Question: Problem: the speed of a car is 85 km in the first hour and 45 km in the second hour . what is the average speed of the car ?

Answer: 65 kmph

Question: Problem: in a room filled with 6 people , all 6 people have exactly 2 siblings in the room . if two individuals are selected from the room at random , what is the probability that those two individuals are not siblings ?

Answer: 3 / 5

Question: Problem: a and b together can do a piece of work in 6 days and a alone can do it in 13 days . in how many days can b alone can do it ?

Answer:
78 / 7 days