Answer:
Step-by-step explanation:
The Simple Interest Equation is
where
A = Total Accrued Amount (principal + interest)
P = Principal Amount
I = Interest Amount
t = Time Period involved in months or years
In this case, we do not know the values of the equation (A and P), but we know the amount of interest accrued
If we define our principal whit this formula, we are able to know the rest of the values:
clearing
replacing
Solving
Answer:
The woman invested $15,000 at 7% interest rate and $5,000 at 6% interest rate.
Step-by-step explanation:
We are given the following in the question:
Let x be the interest earned from 7% interest rate and y be the interest earned from 6% interest rate.
The woman invested has three times as much invested at 7% as she does at 6%.
Thus, we can write the equation:
The total interest is $1,350.
Thus, we can write the equation:
Solving the two equations by substitution method:
Thus, she invested $15,000 at 7% interest rate and $5,000 at 6% interest rate.