Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
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Question: Problem: the average runs scored by a batsman in 30 matches is 50. in the next 15 matches the batsman scored an average of 26 runs. find his average in all the 45 matches ?
Options: a. 31, b. 42, c. 29, d. 97, e. 27

Answer: b


Question: Problem: in what time will a train 120 m long cross an electric pole, it its speed be 121 km / hr ?
Options: a. 2.5, b. 2.7, c. 2.9, d. 3.6, e. 2.1

Answer: d


Question: Problem: a parking garage rents parking spaces for $ 10 per week or $ 25 per month. how much does a person save in a year by renting by the month rather than by the week ?
Options: a. $ 120, b. $ 160, c. $ 220, d. $ 240, e. $ 260

Answer:
a