PYQ Vault
EbooksTutor

Product of the first primes plus 1: prime or composite

This type of question, asked 2 times: CDS 1 2020, CDS 2 2020. All 2 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    CDS 1 2020

    1
    The number 2×3×5×7×11+12 \times 3 \times 5 \times 7 \times 11 + 1 is

    Tap an option to check your answer.

  2. Question 2

    CDS 2 2020

    20
    If An=Pn+1A_n = P_n + 1, where PnP_n is the product of the first nn prime numbers, then consider the following statements : 1. AnA_n is always a composite number. 2. An+2A_n + 2 is always an odd number. 3. An+1A_n + 1 is always an even number. Which of the above statements is/are correct ?

    Tap an option to check your answer.