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).

Calculate prob of sequence nesl when four letters picked without replacement from {a: 1, v: 2, e: 2, n: 1, l: 1, s: 1}.
1/840

What is twenty-one eighths of a centimeter in micrometers?
26250

Let p = 2 + -1. Let c be 16/5 + p/(-5). Suppose 7*m - 4*t - 20 = c*m, -2 = -4*m - 5*t. Solve m*h = 2*h - 5*j - 13, -h - 2*j = 4 for h.

2