I can think of several different ways to include a fifth root in a basic-skills question without the question being beyond test takers' plausible competence. Much depends, of course, on what the other answer choices are. 1. Which of the following most closely approximates 7 to the power 1/5? a. 5/7 b. 16,800 c. 7/5 d. -35 A student who understands the general concept of a what a root is - that is, "2 is the cube root of 4" means that 2 is what one multiplies by itself to yield 4 - and who knows some other fundamentals of number theory can eliminate three of those answers: 7 is positive, so its fifth root also has to be positive, so answer (d) doesn't work; the positive root of a positive integer cannot be greater than the positive integer, so (b) is too darn big; the positive root of a positive integer that's more than 1 really can't be less than 1, so answer (a) doesn't work. That leaves answer (c), and all without calculation.