Final answer:
To find the time it takes for the total amount of pollution to reach 250 kg, we can use the formula for the sum of an arithmetic series: Sn = (n/2)(a + L), where Sn is the sum, n is the number of terms, a is the first term, and L is the last term.
Step-by-step explanation:
This question involves a mathematical concept.
We are given that pollution is being dumped into a lake at a rate that is increasing at a constant rate from 10 kg/year to 40 kg/year until a total of 250 kg has been dumped.
To find the time it takes for the total amount of pollution to reach 250 kg, we can use the formula for the sum of an arithmetic series: Sn = (n/2)(a + L), where Sn is the sum, n is the number of terms, a is the first term, and L is the last term.
Let's plug in the given values: Sn = (n/2)(10 + 40) = 250. Solving this equation will give us the value of n, which represents the number of years it takes for the total amount of pollution to reach 250 kg.