A certain junior class has 3000 students and a certain senior class has 800 students. Among these students, there are 60 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?
Answers.
A) 1/40000	B) 1/3600	C) 9/2000	D) 1/60	E) 1/15
Let's see   Pick 60/3000 first   Then we can only pick 1 other pair from the 800   So total will be 60 / 800 *3000   Simplify and you get 1/40000   1/40000nswer is 1/40000
<result>A</result>
A certain junior class has 3000 students and a certain senior class has 800 students. Among these students, there are 60 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?