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]: Three letters picked without replacement from csmqmzctcmqzct. What is prob of picking 1 c, 1 m, and 1 q?
[EX A]: 6/91

[EX Q]: Calculate prob of sequence bnbq when four letters picked without replacement from {c: 3, u: 1, q: 1, d: 2, b: 5, n: 1}.
[EX A]: 1/858

[EX Q]: Let y = -10 + 42. Calculate the highest common divisor of 16 and y.
[EX A]:
16