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 o(y) = 6*y + 13. Calculate the remainder when 56 is divided by o(3).
[EX A]: 25

[EX Q]: Calculate prob of picking 1 x, 1 r, 1 z, and 1 b when four letters picked without replacement from brrrzaxra.
[EX A]: 2/63

[EX Q]: Two letters picked without replacement from {f: 3, l: 2, s: 4, q: 1}. Give prob of sequence lq.
[EX A]:
1/45