In a city, the current number of literate people is 25,000. If the number of literate males decreases by 5% and the number of lit…
Quantitative Aptitude ·Previously asked in SSC CGL 2025
View the full solved paper: SSC CGL 2025 Tier I - 13 Sep 2025, Shift 1 (13 Sep 2025, Shift 1)
Question
In a city, the current number of literate people is 25,000. If the number of literate males decreases by 5% and the number of literate females increases by 10%, the total literate population becomes 25,250. What is the present number of literate males in the city?
- A. 12,500
- B. 14,000
- C. 15,000 (Correct answer)
- D. 16,500
Correct Answer
Option C — 15,000
Detailed Solution & Explanation
The correct answer is 15,000.
Key Points
- Let literate males = m, so literate females = 25,000 − m.
- The net change is 25,250 − 25,000 = +250, so:
- −0.05m + 0.10(25,000 − m) = 250
- −0.05m + 2,500 − 0.10m = 250
- −0.15m = −2,250 → m = 15,000
- So there are 15,000 literate males and 10,000 literate females.
Additional Information
- Check: males fall by 5% of 15,000 = 750; females rise by 10% of 10,000 = 1,000; net +250 ✓.
- Working with the net change rather than the new total keeps the numbers small and avoids carrying 25,250 through the algebra.
- The alligation method reaches the same answer: the overall change is +1% (250 on 25,000), sitting between −5% and +10%, so males : females = (10 − 1) : (1 − (−5)) = 9 : 6 = 3 : 2, giving 15,000 and 10,000.
प्रश्न (हिन्दी में)
एक शहर में वर्तमान में साक्षर लोगों की संख्या 25,000 है। यदि साक्षर पुरुषों की संख्या में 5% की कमी आती है और साक्षर महिलाओं की संख्या में 10% की वृद्धि होती है, तो कुल साक्षर जनसंख्या 25,250 हो जाती है। शहर में साक्षर पुरुषों की वर्तमान संख्या क्या है?
- A. 12,500
- B. 14,000
- C. 15,000
- D. 16,500
Topics covered: Percentage Linear Equations