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]: Suppose -3*g + g + 19 = -3*c, -g + 4*c = -22. What is the highest common divisor of g and 16?
[EX A]: 2

[EX Q]: Calculate (-105)/(-30)*4/7.
[EX A]: 2

[EX Q]: Three letters picked without replacement from {z: 4, p: 2, a: 3, c: 1, y: 6}. What is prob of sequence ppy?
[EX A]:
1/280