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I think the answer is 54. Option A.

Why is the official answer provided showing option B 53?

Can someone explain why?

Posted from my mobile device
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Tochi12
I think the answer is 54. Option A.

Why is the official answer provided showing option B 53?

Can someone explain why?

Posted from my mobile device

You all are right. The OA is A. Edited. Thank you.
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Bunuel
To a prime number bigger than 2, 1 is added, the result is multiplied by three. What can be the result of these actions?

A. 54.
B. 53.
C. 51.
D. 43.
E. 41.

Different yet easy approach. Working backwards is the best way to solve this question. Since the last step involved multiplying (PRIME+1) number by 3, the answer must be multiple of 3. So that rules out option B, D and E.

A) 54 = 53 + 1. Is 53 prime? YES

Let's examine option C

C) 51 = 50 + 1. Is 50 prime? NO

Thus, answer is option A.
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Bunuel
To a prime number bigger than 2, 1 is added, the result is multiplied by three. What can be the result of these actions?

A. 54.
B. 53.
C. 51.
D. 43.
E. 41.

We can go backward; that is, for the number in a given answer choice, we can divide it by 3, then subtract 1 from the result, and the final answer should be a prime number. Now, let’s check each answer choice.

A. 54

54/3 - 1 = 18 - 1 = 17

Since 17 is a prime, choice A is the correct answer.

Answer: A
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Given: (Pno. + 1)*3 = ? which of the following
This implies that (option choice/3) - 1 should be a prime no.
only A and C are divisible by 3 but C/3 = 17 => 17-1 16 (not a prime no.)
C: 54/3 = 18 => 18-1 = 17 Which is a prime no. => and. is A.(eliminate A - left with C)
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