QUESTION

CSAT

Medium

Reasoning

Prelims 2024

A Question is given followed by two Statements I and II. Consider the Question and the Statements.

There are three distinct prime numbers whose sum is a prime number. Question: What are those three numbers?

Statement-I : Their sum is less than 2323. Statement-II : One of the numbers is 55.

Which one of the following is correct in respect of the above Question and the Statements?

Select an option to attempt

Explanation

Using Statement-I alone: Statement-I tells us that the sum of the three distinct prime numbers is less than 23. The possible prime numbers less than 23 are: 2, 3, 5, 7, 11, 13, 17, 19. The only triplet that satisfies this condition is (3, 5, 11), with the sum 3+5+11=193 + 5 + 11 = 19, which is less than 23 and is prime. Hence, Statement-I alone is sufficient to answer the question.

Using Statement-II alone: Statement-II tells us that one of the numbers is 5.

  • (5, 7, 11) has the sum 5+7+11=235 + 7 + 11 = 23, which is prime.
  • (5, 11, 13) has the sum 5+11+13=295 + 11 + 13 = 29, which is prime.

With Statement-II, we have multiple possible sets of prime numbers (5, 7, 11) and (5, 11, 13), so Statement-II alone does not provide a unique answer.

Trusted by 2L aspirants

Practice UPSC Prelims PYQs Smarter

Practice Now
  • Track accuracy & weak areas
  • See past trends & repeated themes
Start Practicing Now

Crack UPSC with your
Personal AI Mentor

An AI-powered ecosystem to learn, practice, and evaluate with discipline

SuperKalam is your personal mentor for UPSC preparation, guiding you at every step of the exam journey.

Download the App

Get it on Google PlayDownload on the App Store
Follow us

ⓒ Snapstack Technologies Private Limited