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).

Let l = 1 + 7. Solve 4 + l = 3*s for s.
4

Calculate prob of picking 3 a and 1 o when four letters picked without replacement from {a: 1, t: 6, o: 2, m: 4, c: 3}.
0

Suppose 0 = 5*a + 3*q - 104, 0 = 5*a - 0*q - 3*q - 116. Suppose 0 = -b - 3*b + 5*n + 88, b - 3*n - a = 0. Suppose b = -0*f + 2*f. What is the tens digit of f?

1