Question

A bag contains 6 red balls and 3 blue balls. 4 balls are selected at random. find the probability of selecting 4 red balls.

Answer 1

Assuming that the balls are not replaced;


`(6)/(9)* (5)/(8)* (4)/(7)* (3)/(6)`= 5/42

(the numbers are decreasing in the denominator as you are presumably taking out the red balls. In the denominator, there is one less ball each time since you took out a red one).

Therefore, the probability of selected 4 red balls consecutively without replacement is 5/42.

Hope I Helped :)