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 y(a) = -a + 5. Let m be y(3). Solve f + 16 = -0*f - 4*c, -3*c - 12 = -m*f for f.

Answer: 0


Question: Two letters picked without replacement from {l: 1, i: 3, o: 1}. Give prob of picking 1 i and 1 l.

Answer: 3/10


Question: What comes next: -15, -40, -83, -144, -223, -320?

Answer:
-435