The time to complete a standardized exam in the byu-idaho testing center is approximately normal with a mean of 70 minutes and a standard deviation of 10 minutes. using the 68-95-99.7 rule, approximately what percentage of students will complete the exam in under fifty minutes? give your answer accurate to one decimal place.

Aroulette wheel has 38 slots in which the ball can land. two of the slots are green, 18 are red, and 18 are black. the ball is equally likely to land in any slot. the roulette wheel is going to be spun twice, and the outcomes of the two spins are independent.the probability that it lands one time on red and another time on black in any order is(a) 0.5 (b) 0.25 (c) 0.4488 (d) 0.2244