Q. A fair die is tossed eight times. The probability that a third six is observed on the eight throw, is
A) $\frac{\ ^{7}C_{2} \times 5^{5}}{6^{7}}$
B) $\frac{\ ^{7}C_{2} \times 5^{5}}{6^{8}}$
C) $\frac{\ ^{7}C_{2} \times 5^{5}}{6^{6}}$
D) None of these
Explanation
(b)
Required probability$= \ ^{7}C_{2}\left( \frac{1}{6} \right)^{2}\left( \frac{5}{6} \right)^{5} \times \frac{1}{6}$
$= \frac{\ ^{7}C_{2} \times 5^{5}}{6^{8}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.