A rifleman is firing at a distance target and hence has only 10% chance of hitting it. Find the number of rounds; he must fire in order to have more than 50% chance of hitting it at least once.

Explanation

`P(` hitting in one shot`)` `= 10/100 = 1/10 ldots ldots` Given


`therefore,` the `P(` Not hitting `)` `=1-(1/10) = 9/10`


`P(` hitting at least once in `n` shots `)` `=1-(9/10)^n`


According to the given condition `1-(9/10)^n = 1/2`


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