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]: Suppose -s = 4*r - 45, -s - r + 4*r = -38. Calculate the remainder when 121 is divided by s.
[A]: 39


[Q]: Let u = -26 - -12. Let d = u - -24. What is the units digit of (2 - d)*2/(-4)?
[A]: 4


[Q]: Convert 0.4370841cm to micrometers.
[A]:
4370.841