There are four types of weights, namely 1 kg, 2 kg, 5 kg and 10 kg. What is the maximum number of different ways one can measure…
Quantitative Aptitude ·Previously asked in UPSC Civil Services Examination 2026
View the full solved paper: GS Paper II
Question
There are four types of weights, namely 1 kg, 2 kg, 5 kg and 10 kg. What is the maximum number of different ways one can measure 20 kg, if at least eight but not more than eleven weights of 1 kg are to be used while measuring?
- A. 7
- B. 8 (Correct answer)
- C. 9
- D. 10
Correct Answer
Option B — 8
Detailed Solution & Explanation
The correct answer is Option B (8 ways).
Key Points
- Weights available: 1, 2, 5, 10 kg; total needed = 20 kg using 8 to 11 one-kg weights.
- For each allowed count of 1-kg weights, the remaining kilograms must be formed from 2s, 5s and 10s, and counting the valid partitions across 8, 9, 10 and 11 one-kg weights gives 8 distinct ways.
Additional Information
- Restricting the number of 1-kg weights is what bounds the count to 8 → Option B.