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: What is prob of picking 2 f when two letters picked without replacement from iiiiffll?
Example Output: 1/28

Example Input: Let b be ((-4)/(-6))/(4/(-6)). Let l be ((b - -1) + 0)*-1. Solve -3*d = 4*x + 2*d + 45, 5*x - 3*d + 10 = l for x.
Example Output: -5

Example Input: Two letters picked without replacement from bbrrnbbrrxbr. Give prob of picking 2 r.
Example Output:
5/33