A and B play a game where each is asked to select a number from 1 to 16. If the two numbers match , both of them win a prize. Find the probability that they will not win a prize in a single trial.  Choose the correct answer:
A) 15 / 16
B) 1 / 16
C) 7 / 8
D) 9 / 8
E) none of these

Rationale: explanation : a and b win a prize , only if both a and b select the number . so , if a chooses a number , b has to select the same number . hence , it is problem on dependent event . let a select a number . , then p ( a ) = 1 / 16 = probability of a . now , b selects the same number after a has already selected that number . then , p ( b / a ) = 1 / 1 = dependent probability of b given a has occurred . p ( ab ) = probability of winning a prize by both a and b is : - = > p ( a ) x p ( ab ) . = > ( 1 / 16 ) x 1 = 1 / 16 . hence , the probability of not winning a prize is : - = 1 - ( 1 / 16 ) . = 15 / 16 . answer : a
Answer: A