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).

Example Input: Four letters picked without replacement from zczcuzuzuzccuzzcc. Give prob of picking 4 c.
Example Output: 3/476

Example Input: Convert 39.12191 tonnes to milligrams.
Example Output: 39121910000

Example Input: What is next in 30, 29, 26, 21, 14, 5?
Example Output:
-6