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: Solve 4*f + 4*z = 0, 0 = -28*f + 29*f - 2*z + 15 for f.

Answer: -5


Question: Two letters picked without replacement from dioodwoliowowwii. Give prob of sequence ow.

Answer: 1/12


Question: Let a = 3 - 4. Let p be a + 2/1*-1. Find the common denominator of p/(-6)*(-98)/(-18) and -71/10.

Answer:
90