perplexus.info :: Probability : 7 come zero

7 come zero (Posted on 2018-06-28)

Let N be a randomly chosen 5-digit number.

a. What is the probability that N contains at least one zero?
b. What is the probability that N contains at least one 7?
c. What is the probability that it contains exactly one zero and one 7?

d. Generalize the above questions for a n-digit number , n>1.

No Solution Yet Submitted by Ady TZIDON

Rating: 5.0000 (1 votes)

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re: Part C (spoiler)...............reconsider

| Comment 3 of 5 |

(In reply to Part C (spoiler) by Steve Herman)

Randomly chosen 5 digit number usually implies no zero as the most significant digits.

Otherwise both a. and b. would rend the same answer.

Posted by Ady TZIDON on 2018-06-28 10:10:09

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