X receives three coins of different denominations from among 1, 2, 5, 10 and 20. If the total amount received by X is m, does X r…
Mental Ability & Logical Reasoning ·Previously asked in UPSC Civil Services Examination 2026
View the full solved paper: GS Paper II
Question
Directions: The question is followed by two statements. Answer using the codes given in the options.
X receives three coins of different denominations from among 1, 2, 5, 10 and 20. If the total amount received by X is m, does X receive a coin of denomination 5?
Statement I: m is not a prime number.
Statement II: The sum of the digits of m is greater than 5.
- A. The question can be answered using one of the statements alone, but cannot be answered using the other statement alone. (Correct answer)
- B. The question can be answered using either statement alone.
- C. The question can be answered using both the statements together, but cannot be answered using either statement alone.
- D. The question cannot be answered even using both the statements together.
Correct Answer
Option A — The question can be answered using one of the statements alone, but cannot be answered using the other statement alone.
Detailed Solution & Explanation
The correct answer is Option A (one statement alone suffices, the other does not).
Key Points
- Any 3 distinct denominations from {1, 2, 5, 10, 20} give sums: 8, 13, 16, 17, 23, 26, 27, 31, 32, 35.
- Statement II (digit-sum of m > 5) alone is sufficient: the qualifying totals are 8, 16, 17, 26, 27, 35 — and *every one of these combinations contains a 5-coin*, so the answer is definitely "Yes".
- Statement I (m not prime) alone is insufficient: m = 32 (= 2+10+20) is non-prime but has no 5-coin, while m = 8 (= 1+2+5) is non-prime and does contain a 5.
Additional Information
- Since exactly one statement settles the question and the other does not, the answer is Option A.