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 bbbsbbbsbbkkkssbbb. What is prob of picking 2 s and 2 b?
11/102

Evaluate (-7)/6 + 2 + 9/(-27).
1/2

Calculate prob of picking 1 d, 2 n, and 1 w when four letters picked without replacement from xcwdxdllwnnxwdnn.

27/910