Q. A pair of fair dice is thrown independently three times. The probability of getting a score of exactly 9 twice is
A) $\frac{1}{729}$
B) $\frac{8}{9}$
C) $\frac{8}{729}$
D) $\frac{8}{243}$
Explanation
(d)
Probability of getting score 9 in a single throw
$= \frac{4}{36} = \frac{1}{9}$
Probability of getting score 9 exactly in double throw
$= {\ ^{3}C}_{2} \times \left( \frac{1}{9} \right)^{2} \times \frac{8}{9} = \frac{8}{243}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.