A password of a computer used five digits where they are from 0 and 9. What is the probability that the password solely consists of prime numbers and zero?
A 1/32
B 1/16
C 1/8
D 2/5
E ½
OA is E
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Anurag@Gurome
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Without any restriction, each of the 10 digits can go to any of the 5 places. Hence, total number of possible passwords = 10^5hey_thr67 wrote:A password of a computer used five digits where they are from 0 and 9. What is the probability that the password solely consists of prime numbers and zero?
With the restriction mentioned we are limited only with 0, 2, 3, 5, and 7. Each of this five digits can go to any of the 5 places. Hence, total number of restricted outcome = 5^5
Hence, required probability = (5^5)/(10^5) = (5/10)^5 = (1/2)^5 = 1/32
The correct answer is A.
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sam2304
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Are you sure the OA is E ?
total number of combinations = 10^5
total allowed combinations with prime numbers and 0 = 5^5
Prob = 5^5/2^5*5^5 = 1/2^5 = 1/32
IMO A.
total number of combinations = 10^5
total allowed combinations with prime numbers and 0 = 5^5
Prob = 5^5/2^5*5^5 = 1/2^5 = 1/32
IMO A.
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