How many ways can the letters in the word "mathematics" be arranged?
+
What is the probability that out of 10 randomly selected students, exactly 3 have blue eyes, given that the probability of a student having blue eyes is 0.25?
+
Math question: Find the 4th order derivative of f(x) = e^(2x) - x^3 + 5x, where e represents Euler's number.