Question

15 coupons are numbered 1....15 respectively.7 coupons are selected at random 1 at a time with replacement.The probability that the largest number appearing is 9?

• A. (8/15)⁷
• B. (3/5)⁷
• C. (9/16)⁷
• D. 9⁷-8⁷/15⁷

Answer 1

The correct option is D

9⁷-8⁷/15⁷

Total sample space:${15}^7$

favorable cases :$9^7-8^7$

$P\left(E\right)=\frac{9^7-8^7}{{15}^7}$