The population of a town increases by 80% in the first year and further it…
2018
The population of a town increases by 80% in the first year and further it increases by 20% in the second year. The overall increase percentage in population in two years is
- A.
95%
- B.
80%
- C.
100%
- D.
116%
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Correct answer: D
To find the overall percentage increase when a population grows sequentially, you cannot simply add the percentages. Instead, you must calculate the effect of each increase on the new total.
Step-by-Step Analysis
Assume an initial value: Let the initial population be 100.
First-year increase (80%):
Increase = 80% of 100 = 80.
New population = 100 + 80 = 180.
Second-year increase (20%):
Increase = 20% of the new population (180).
Calculation: 0.20 × 180 = 36.
New population = 180 + 36 = 216.
Calculate overall percentage increase:
Total increase = Final population - Initial population = 216 - 100 = 116.
Percentage increase = (Total increase / Initial population) × 100
(116 / 100) × 100 = 116%.