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).

Four letters picked without replacement from {u: 9, s: 9}. Give prob of picking 3 s and 1 u.
21/85

What is next in 64, 117, 216, 367, 576, 849, 1192, 1611?
2112

How many micrometers are there in one tenth of a meter?

100000