Originally Posted by

**a69356** Hi All,

I have a question related to probability :-

Q - Ten tickets are numbered 1,2,3 ..... 10 .Six tickets are selected at random one at a time with replacement.The probablity that the largest number appearing on the selected ticket is 7 is :-

Sol - As per my understanding, I tried solving the above question in the way mentioned below:-

Six tickets can be drawn in the 10.10.10.10.10.10

Sample space for above question is n(s) = 10 ^6

As the largest number appearing on the selected ticket is 7.

So out of the selected 6 tickets one must be 7 and rest 5 were either equal to or less than 7. These can drawn in 7.7.7.7.7 = 7^5.

Hence n(e) = 7^5

Therefore the probability p(e) = n(e)/n(s) = (7^5)/(10^6)

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But the book Answer is - (7^6 - 6^6)/10^6.

Please help me in figuring out the right way in solving the above question.

Any help would be greatly appreciated.

Thanks,

Ashish