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).
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Question: Let b be 4 + -1 + 72490/16. Let r = 4524 - b. Find the common denominator of 4 + -2 - (-83)/(-4) and r.

Answer: 8


Question: What is -7.84 - -0.0455?

Answer: -7.7945


Question: What is prob of picking 1 o and 3 f when four letters picked without replacement from offeonffeooffeoop?

Answer:
6/119