TASK DEFINITION: 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).
PROBLEM: Calculate -2 divided by 40.

SOLUTION: -1/20

PROBLEM: What is prob of picking 3 o and 1 z when four letters picked without replacement from zozzzozo?

SOLUTION: 1/14

PROBLEM: Let a be ((-2)/3)/(1/3). Let p(b) = b**2 - 1 + 3*b + 2*b**2 + 0*b - b. What is the units digit of p(a)?

SOLUTION:
7