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.

Q: Problem: if 9 / ( 1 + 4 / x ) = 1, then x =
Options: a. 3, b. 1 / 2, c. 1 / 3, d. - 1 / 3, e. - 3

A: b
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Q: Problem: a bag contains 10 green and 8 white balls. if two balls are drawn simultaneously, the probability that both are of the same colour is
Options: a. 8 / 15, b. 21 / 44, c. 3 / 5, d. 11 / 15, e. 7 / 15

A: b
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Q: Problem: the value of a machine depreciates at 20 % per annum. if its present value is rs. 1, 50,000, at what price should it be sold after two years such that a profit of rs. 28,000 is made ?
Options: a. 328897, b. 120000, c. 877888, d. 124000, e. 188871

A:
d
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