Question

for a given interest rate, simple interest varies jointly as the principal and time. if $3000 left in an account for 3 years earned interest of $540, then how much interest woukd be earned in 4 years?

Answer 1

The interest for 4 years on a principal of $3,000 at an annual rate of 6% would be $720.

Step-by-step explanation:

The question asks how much interest would be earned on a principal of $3,000 over 4 years, given that $540 was earned over 3 years. We know that simple interest is calculated with the formula Interest = Principal × rate × time. From the given information, we can find the rate first and then use it to calculate the interest for 4 years.

The interest earned over 3 years is $540, so if we set up the equation: $540 = $3,000 × rate × 3 years. We can solve for the rate by dividing $540 by ($3,000 × 3), which gives us a rate of 0.06 or 6% per annum.

Now, we can find the interest for 4 years using the found rate: Interest = $3,000 × 0.06 × 4 years = $720. So, using the formula and the rate previously determined, the interest earned in 4 years would be $720.

Answer 2

720 dollars

You get this by 540/3*4

I hope I helped you.