A certain junior class has 1000 students and a certain senior class has 800 students. Among these students, there are 40 siblings pairs each consisting of 1 junior and 1 senior. If 1 student is to be selected at random from each class, what is the probability that the 2 students selected will be a sibling pair?	Options.
A) 3/40000 B) 1/3600 C) 1/20000 D) 1/60 E) 1/15
Let's see   Pick 40/1000 first   Then we can only pick 1 other pair from the 800   So total will be 40 / 800 *1000   Simplify and you get 1/20000   Answer is 1/20000
<result>C</result>
A certain junior class has 1000 students and a certain senior class has 800 students. Among these students, there are 40 siblings pairs each consisting of 1 junior and 1 senior. If 1 student is to be selected at random from each class, what is the probability that the 2 students selected will be a sibling pair?