A rifleman is firing at a distant target ansd hence, has only `10%` chances of hitting it. Find the number of rounds, he must fire in order to have more than `50%` chances of hitting it at least once.
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Let a rifieman fires n number of rounds. Probability of hitting the targeet, `p=1/10.` `therefore` Probability of not hitting the target, `q=1-1/10=9/10.` `therefore` Probability of hitting the target at least once `=1-((9)/(10))^(n)` Given that `1-((9)/(10))^(n)gt1/2` `therefore((9)/(10))lt1/2` So, the least value of n is 7.
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