Q. Seven chits are numbered 1 to 7. Four chits are drawn one by one with replacement. The probability that the least number appearing on any selected chit is 5, is
A) $\left( \frac{3}{7} \right)^{4}$
B) $\left( \frac{6}{7} \right)^{3}$
C) $\frac{5 \bullet 4 \bullet 3}{7^{3}}$
D) $\left( \frac{3}{4} \right)^{3}$
Explanation
(a)
The probability that the number appearing on the selected chit is greater than or equal to 5 is 3/7
$\therefore$ Required probability$= \left( \frac{3}{7} \right)^{4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.