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 -6 = -t - 2*t. Suppose 4*h - 10 = -t*r, -h - 3*h + 3*r + 5 = 0. Suppose 19 + 15 = h*g. What is the greatest common divisor of g and 153?
[EX A]: 17

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

[EX Q]: Let l(z) be the third derivative of z**5/60 - z**4/24 - z**3/2 - 2*z**2. Let h be l(3). Suppose 16 = h*w + 1. What is the units digit of w?
[EX A]:
5