Question

Phyllis invested $10,500 a portion earning a simple interest rate of 3(1/5)% per year and the rest earning a rate of 3% per year, after one year the total interest earned on these investments was $333.00. How much money did she invest at each rate?

Answer 1

To solve this problem, we can use the formula for simple interest, which is:

I=Prt

where I is the interest, P is the principal, r is the rate, and t is the time. We can let x be the amount invested at 3(1/5)% per year, and 10,500 - x be the amount invested at 3% per year. Then we can write an equation as follows:

333=x×0.032×1+(10,500−x)×0.03×1

Simplifying and solving for x, we get:

333=0.032x+315−0.03x

0.002x=18

x=9,000

Therefore, Phyllis invested $9,000 at 3(1/5)% per year and $10,500 - $9,000 = $1,500 at 3% per year.