In one year, population of a village increased by 10% and in next year, it…
2025
In one year, population of a village increased by 10% and in next year, it decreased by 10%. If at the end of 2nd year, the population was 7920, what was it in beginning?
Answer: B. 8000 — Solution: Let the original population be P. After a 10% increase: population = P × 1.10 = 11P/10. After a 10% decrease next year: population = (11P/10) × 0.90…
- A.
7600
- B.
8000
- C.
9000
- D.
None of these
Attempted by 22 students.
Show answer & explanation
Correct answer: B
Solution:
Let the original population be P.
After a 10% increase: population = P × 1.10 = 11P/10.
After a 10% decrease next year: population = (11P/10) × 0.90 = (11P/10) × (9/10) = 99P/100.
Given final population is 7920, so 99P/100 = 7920. Solve for P: P = 7920 × 100/99 = 8000.
Answer: 8000
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