Given a simple high-school level math question, you are required to solve it and provide the final answer. The final answer is always a single number. These questions can range from a variety of topics like simple arithmetic, solving equations, converting a quantity from one unit to another, finding remainders/GCD/LCM, finding probabilities etc. Each question has only one correct answer. This answer can be a positive or negative integer, a fraction or a decimal number. If the answer is a negative number use the hyphen (e.g. -42) symbol for the minus sign. For decimal numbers, do not add extra zeros after the decimal point. For fractional numbers, separate the numerator and denominator using a forward slash (e.g. 3/25).

Q: Four letters picked without replacement from bbbsbbbsbbkkkssbbb. What is prob of picking 2 s and 2 b?

A: 11/102
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Q: Convert 39.12191 tonnes to milligrams.

A: 39121910000
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Q: Solve 96*r - 13 = 91*r + 2*u, 3*u - 12 = -3*r for r.

A:
3
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