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).

[EX Q]: Let u(w) be the first derivative of -w**2/2 + 9*w - 1. What is the lowest common multiple of u(8) and 6?
[EX A]: 6

[EX Q]: Solve -5*i - 5*r - 50 = 0, -r + 5 = -4*i - 10 for i.
[EX A]: -5

[EX Q]: Calculate prob of sequence ppy when three letters picked without replacement from {y: 2, p: 2}.
[EX A]:
1/6