Three defective bulbs got mixed up with seven good ones. If two bulbs are selected at random, what is the probability that both are good?
-
A.
(frac{3}{7}) -
B.
(frac{21}{50}) -
C.
(frac{7}{15}) -
D.
(frac{49}{100})
Correct Answer: Option C
Explanation
(P(text{both bulbs are good}) = frac{7}{10} times frac{6}{9})
= (frac{7}{15})