Three distinct numbers are selected from first 100 natural numbers. Th...
If a number is divisible by both 2 and 3, then it is a multiple of 6.
Now, I assume that if a number is chosen, it is not available for choosing again.
Now, multiples of 6 are 6, 12, 18,...., 96...i.e. 16 numbers
P(1st) => 16/100
P(2nd\1st is multiple of 6) => 15/99
P(3rd\1st and 2nd is multiple of 6) => 14/98
Hence, 16/100 x 15/99 x 14/98 => 4/25 x 5/33 x 1/7
i.e. 4/5 x 1/33 x 1/7 => 4/1155
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Three distinct numbers are selected from first 100 natural numbers. Th...
To solve this problem, we need to find the probability of selecting three distinct numbers from the first 100 natural numbers that are divisible by both 2 and 3.
Total Possible Outcomes:
The total number of ways to select 3 distinct numbers from the first 100 natural numbers is given by the combination formula: C(100, 3) = 100! / (3! * (100 - 3)!) = 100 * 99 * 98 / (3 * 2 * 1) = 161,700.
Favorable Outcomes:
Out of the first 100 natural numbers, half of them are divisible by 2 (since every other number is divisible by 2), and one-third of them are divisible by 3 (since every third number is divisible by 3).
The numbers that are divisible by both 2 and 3 are the numbers that are divisible by their least common multiple, which is 6. We can determine the number of such numbers by dividing 100 by 6 and taking the floor value: ⌊100/6⌋ = 16.
Therefore, there are 16 numbers from 1 to 100 that are divisible by both 2 and 3.
Probability Calculation:
The probability of selecting three distinct numbers that are divisible by both 2 and 3 can be calculated as the ratio of the number of favorable outcomes to the total number of possible outcomes:
Probability = Number of Favorable Outcomes / Total Number of Possible Outcomes
Probability = 16 / 161,700
Simplifying this fraction, we get:
Probability = 4 / 40,425
Dividing both the numerator and denominator by 5, we get:
Probability = 4 / 8,085
Further simplifying by dividing both the numerator and denominator by 15, we get:
Probability = 4 / 1,355
Finally, dividing both the numerator and denominator by 5, we arrive at:
Probability = 4 / 1,155
Therefore, the probability that all three numbers selected are divisible by both 2 and 3 is 4/1,155, which corresponds to option D.
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