if a number is drawn from the first 1000 positive integers, what is the probility of selecting a refined number.
1) any refind number must be divisible by 22
2) A refined number is any even multiple of 11
at the first sight ans seems D but it is B, experts please shed some light
probability
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Meybe the trick is this: "any refind number must be divisible by 22" but this doesn't define what a refind number is.vipulgoyal wrote:if a number is drawn from the first 1000 positive integers, what is the probility of selecting a refined number.
1) any refind number must be divisible by 22
2) A refined number is any even multiple of 11
For example: must be divisible by 22, AND BY 3.
Option B, on the other, hand defines what a refined number is...
My opinion
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I guess this is a DS problem posted in wrong forum.vipulgoyal wrote:if a number is drawn from the first 1000 positive integers, what is the probility of selecting a refined number.
1) any refind number must be divisible by 22
2) A refined number is any even multiple of 11
Anyway, the required probability = (Number of refined numbers in first 1000 positive integers)/1000
Hence, we need to know what is refined number and how many of them are in the first 1000 positive integers.
Statement 1: This is not a complete definition of refined number. There may be some other criteria like divisible by 3 or perfect square or sum of digits equal to 9 to be a refined number. Hence, we cannot find out the number of refined number in the first 1000 positive integers.
Not sufficient
Statement 2: Now we know that any even multiple of 11 is a refined number. Hence, we can find out the number of even multiples of 11 in the first 1000 positive integers.
Sufficient
The correct answer is D.
Anurag Mairal, Ph.D., MBA
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