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.
--------
Question: Problem: 40 is subtracted from 60 % of a number, the result is 50. find the number ?
Options: a. 150, b. 330, c. 277, d. 279, e. 712

Answer: a


Question: Problem: the mean of 50 observations is 200. but later he found that there is decrements of 34 from each observations. what is the the updated mean is ?
Options: a. 165, b. 166, c. 190, d. 198, e. 199

Answer: b


Question: Problem: how many different positive integers exist between 10 ^ 3 and 10 ^ 4, the sum of whose digits is equal to 2 ?
Options: a. 6, b. 7, c. 5, d. 4, e. 18

Answer:
d