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 c be (5 + -4)/((-1)/3). What is the tens digit of c - (-6)/3 - -13?

Answer: 1


Question: In base 14, what is 2 - -129?

Answer: 12b


Question: Two letters picked without replacement from hppfa. Give prob of sequence hf.

Answer:
1/20