2024 CSAT, all questions
UPSC Prelims 2024 · CSAT
Question 77: Logical Reasoning and Mental Ability
If in a certain code, ‘ABCD’ is written as 24 and ‘EFGH’ is written as 1680, then how is ‘IJKL’ written in that code?
a11880
b11240
c7920
d5940
AnswerUPSC’s answer is (a).
ABCD = 24 is the product of the letters' positions in the alphabet, 1 × 2 × 3 × 4 = 24, and EFGH = 5 × 6 × 7 × 8 = 1680. Following the same rule, IJKL uses positions 9, 10, 11 and 12: 9 × 10 × 11 × 12 = 990 × 12 = 11,880. Remember to test a coding rule on every given example before applying it.
Why each option is right or wrong
- (a) Right. 9 × 10 × 11 × 12 = 11,880.
- (b) Wrong. 11,240 does not equal the product 9 × 10 × 11 × 12.
- (c) Wrong. 7,920 is 8 × 9 × 10 × 11, the product for the wrong set of letters (HIJK).
- (d) Wrong. 5,940 is half of the correct product; it is not 9 × 10 × 11 × 12.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2024, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.