Question: a box contains 2 red balls and 5 black balls . one by one , every ball is selected at random without replacement . what is the probability that the fourth ball selected is black ?
A) 1 / 4
B) 7 / 5
C) 1 / 2
D) 5 / 8
E) 2 / 3
Correct answer: B
Grade: 7 | Topic: Statistics and Probability | Difficulty: Easy | Standard: 7.SP.C.7