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).

Input: Consider Input: Calculate prob of sequence nesl when four letters picked without replacement from {a: 1, v: 2, e: 2, n: 1, l: 1, s: 1}.

Output: 1/840


Input: Consider Input: Suppose p - 4*p = 0. Suppose -4*v + 0*v + 17 = -l, 4*l + 4 = p. Suppose -3*m + 55 = -17. Solve -5*r + v = m for r.

Output: -4


Input: Consider Input: Four letters picked without replacement from {f: 4, m: 1, g: 5}. Give prob of picking 4 f.


Output: 1/210