If a person selects a book at random from a shelf containing 5 novels, 3 biographies, and 2 science books, what is the probability that the book selected is not a novel?
Instruction: Calculate the probability of selecting a book that is not a novel from the shelf.
Context: This question tests the candidate's ability to calculate the complement of a given probability.
Updated
Official answer
Assuming each of the ten individual books is equally likely to be selected, P(not a novel) = 1−5/10 = 1/2 = 50%.
Direct counting agrees: the three biographies and two science books give five non-novels out of ten. Choosing a genre uniformly first would be a different sampling procedure; the presence of three genres does not make their individual books equally likely under that procedure.