The present population of a town is 200000. The population will increase by 10% in the first year and 15% in the second year. The population of the town after two years will be:

1. 253000

2. 235000

3. 203500

4. 352000

Given,

P = 200000

r₁ = 10% p.a.

r₂ = 15% p.a.

By formula,

Population after two years = $P \times \Big(1 + \dfrac{r$1}{100}\Big) \times \Big(1 + \dfrac{r2}{100}\Big)

Substituting the values in formula,

$\text{Population after two years }=200000 \times \Big(1 + \dfrac{10}{100}\Big) \times \Big(1 + \dfrac{15}{100}\Big) \\[1em] =200000 \times \Big(\dfrac{100 + 10}{100}\Big) \times \Big(\dfrac{100 + 15}{100}\Big) \\[1em] =200000 \times \Big(\dfrac{110}{100}\Big) \times \Big(\dfrac{115}{100}\Big) \\[1em] =200000 \times \Big(\dfrac{11}{10}\Big) \times \Big(\dfrac{23}{20}\Big) \\[1em] =200000 \times 1.10 \times 1.15\\[1em] =253000.$

Hence, option 1 is correct option.