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 {w: 2, k: 1, o: 1, a: 2, b: 2}. What is prob of picking 1 k, 2 a, and 1 b?
1/35

Suppose 4*i + i = 45. Suppose 3*u = i*u - 132. Let v = -82 + 147. Calculate the remainder when v is divided by u.
21

Four letters picked without replacement from vjxsxjsjj. What is prob of sequence jxvx?

1/378