A country's population is growing at a constant rate of 2 percent per annum. Using the rule of 70, the approximate doubling time of this population is:
- A 25 years
- B 35 years ✓
- C 50 years
- D 70 years
Correct answer: B. 35 years
Explanation
The rule of 70 states that doubling time equals 70 divided by the annual growth rate percentage. At 2 percent growth, doubling time is 70/2 = 35 years. This is a standard demographic calculation used to project population growth.
Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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