5. Ten Fibonacci numbers are split into three sets: A = {1, 2}, B = {3, 5, 8}, and C = {13, 21, 34, 55, 89}. One number is chosen at random from each set. What is the probability that their sum is odd?

Which of the following is the major negative aspect of crossover designs for research studies? a. prohibitive cost b. residual effects c-subject drepout d. incomplete randomization e. large sample size required