A bird population is 1260 after a 40% decline. What was the population before the decline? Enter the number of birds.
Ճիշտ պատասխան
2100
Բացատրություն
A 40% decline leaves 60% of the old population, so 1260 / 0.60 = 2100. Adding 40% of 1260 gives 1764, which cannot restore a change based on the larger old population.