Question

20% less than Year 1 population = Year 2 population
% of Year 1 population = Year 2 population

Answer 1

To express Year 2 population as a percentage of Year 1 population based on the information provided, let's break it down mathematically.

1. Let's denote the Year 1 population as \( P_1 \).
2. According to the statement "20% less than Year 1 population = Year 2 population", we can express Year 2 population \( P_2 \) as:
\[
P_2 = P_1 - 0.20 \times P_1 = 0.80 \times P_1
\]

3. To find the percentage of Year 1 population that Year 2 population represents, we can set up the following equation:
\[
\text{Percentage of Year 1 population that Year 2 population is} = \left( \frac{P_2}{P_1} \right) \times 100\%
\]

4. Substituting the expression for \( P_2 \):
\[
\text{Percentage} = \left( \frac{0.80 \times P_1}{P_1} \right) \times 100\%
\]

5. Simplifying this gives:
\[
\text{Percentage} = 0.80 \times 100\% = 80\%
\]

Thus, Year 2 population is **80% of Year 1 population**.