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).

[Q]: What is (3/2)/((-21)/(-28) - -3)?
[A]: 2/5


[Q]: Suppose 4*n + 20 = -0*n. Let j = -5 - n. Let m be (60/4)/(1 - j). Calculate the highest common divisor of 15 and m.
[A]: 15


[Q]: In base 12, what is -1 - -432?
[A]:
431