For each of the three years from 2010 to 2012, the population of town X decreased by 8% per year, and the population of town Y increased by 12% per year.

At the end of 2012, the populations of these two towns were equal.

Determine the ratio of the population of town X (call it [tex]P_X[/tex]) to the population of town Y (call it [tex]P_Y[/tex]) at the beginning of 2010.



Answer :

Sure! Let's work through the problem to determine the ratio of the population of town X (Px) to the population of town Y (Py) at the beginning of 2010.

### Step-by-Step Solution:

1. Understand the problem setup:
- Town X's population decreases by 8% per year from 2010 to 2012.
- Town Y's population increases by 12% per year from 2010 to 2012.
- Populations of both towns are equal at the end of 2012.

2. Define the population changes:
- For town X: If the population at the beginning of 2010 is Px, then at the end of each year, it decreases to 92% of the previous year. Thus, at the end of 2012, it is:
[tex]\[ \text{Population of X at end of 2012} = Px \times (0.92^3) \][/tex]
- For town Y: If the population at the beginning of 2010 is Py, then at the end of each year, it increases to 112% of the previous year. Thus, at the end of 2012, it is:
[tex]\[ \text{Population of Y at end of 2012} = Py \times (1.12^3) \][/tex]

3. Equate the populations at the end of 2012:
- Since the populations are equal at the end of 2012:
[tex]\[ Px \times (0.92^3) = Py \times (1.12^3) \][/tex]

4. Solve for [tex]\( \frac{Px}{Py} \)[/tex]:
- Rearrange the equation to solve for the ratio of [tex]\( Px \)[/tex] to [tex]\( Py \)[/tex] at the beginning of 2010:
[tex]\[ \frac{Px}{Py} = \frac{1.12^3}{0.92^3} \][/tex]

5. Calculate the ratio:
- By calculating the above ratio, we get:
[tex]\[ \frac{Px}{Py} = 1.804224541793376 \][/tex]

### Conclusion:
The ratio of the population of town X (Px) to the population of town Y (Py) at the beginning of 2010 is approximately [tex]\( \boxed{1.804224541793376} \)[/tex].