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).

Example Input: Four letters picked without replacement from arkkallleaakkkra. What is prob of sequence lkak?
Example Output: 5/728

Example Input: Let r(m) = 2*m**2 + 5*m + 2. Let s be r(-3). Let y(l) = l. Let n be y(s). Suppose d - n = -2*a, -4*d - 3*a + 18 = -d. What is the units digit of d?
Example Output: 7

Example Input: Suppose -s = 4*r - 45, -s - r + 4*r = -38. Calculate the remainder when 121 is divided by s.
Example Output:
39