If the population of a town has increased from 60,000 to 65,000, then the…
2018
If the population of a town has increased from 60,000 to 65,000, then the increase in population (in percent) is:
Attempted by 2 students.
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Percentage increase (or decrease) is always measured against the ORIGINAL value, before the change: Percentage change = (Increase in value ÷ Original value) × 100. The original value is the quantity BEFORE the change — never the new value, and never an average of the two.
The population changed from 60,000 (original) to 65,000 (new), so the increase is 65,000 − 60,000 = 5,000.
Apply the formula: Percentage increase = (Increase ÷ Original population) × 100 = (5,000 ÷ 60,000) × 100.
Simplify the fraction: 5,000⁄60,000 reduces to 5⁄60, which reduces further to 1⁄12.
Multiply by 100: 1⁄12 × 100 = 100⁄12 = 8, remainder 4, i.e. 8 4⁄12 = 8 1⁄3.
So the population increased by 8 1⁄3 %.
Check by reversing the calculation: 8 1⁄3 % of 60,000 = 25⁄3 % × 60,000 = 25 × 200 = 5,000, exactly the increase used above — confirming the result.