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).

What is prob of picking 3 o and 1 p when four letters picked without replacement from pooooopppppoo?
42/143

Calculate prob of picking 1 t, 1 k, and 1 z when three letters picked without replacement from {t: 1, z: 2, k: 1}.
1/2

Suppose -b - 3*g = 2*b - 231, -310 = -4*b - 2*g. Suppose -5*k = -10, 5*k + b = 2*u - 0*u. What is the units digit of u?

4

