a city poplation of 350,000 the poplation has decreased by 30% in the past ten years what was the poplation of the city ten years"
+166 I'm guessing the question is asking for the population ten years ago.
Since the population has decreased by 30%, the population now (350,000) is 70% = 7/10 of the original population. So then,
\((\text{population 10 years ago})\cdot\frac{7}{10}=350,000\).
Multiplying both sides by 10/7 to cancel out the fraction gives
\(\text{population 10 years ago} = 350,000\cdot\frac{10}{7}=\boxed{500,000}\)
