Question

A bag contains 11 orange cubes and 9 black cubes. Once a cube is picked, it is not replaced. What is the probability of choosing 2 black cubes?

A. 3/10 B. 3/20 C. 14/95 D. 18/95

Answer 1

`|\Omega|=20\cdot19=380\\ |A|=9\cdot8=72\\\\ P(A)=(72)/(380)=(18)/(95)\Rightarrow \text{D}`