The population of a town increases at the rate of 5% annually. If the present population is 4410, what was it 2 years ago ?एक कस्बे की जनसंख्या 5% वार्षिक दर से बढ़ती है, यदि कस्बे की वर्तमान जनसंख्या 4410 हो, तो 2 वर्ष पहले जनसंख्या कितनी थी ?

1. A3600
2. B3800
3. C4000
4. D4200

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: C. 4000

Explanation

Let the population 2 years ago be P. Then P × (21/20)² = 4410, so P = 4410 × 400/441 = 10 × 400 = 4000.माना 2 वर्ष पहले जनसंख्या P थी। तब P × (21/20)² = 4410, अतः P = 4410 × 400/441 = 10 × 400 = 4000।