If the simple interest on $3,000 for 8 years is $1,680, then what is the interest rate?

We need to use the formula for simple interest which is
I= prt
Where I is the amount of money you earned or pay in interest
p is the principal, the amount you deposited or borrowed
r is the interest rate expressed as a decimal
t is time in terms of years

In this problem, I= 1,680
p= 3000
t= 8
'. r is what we are looking for.

Substituting the numbers into the simple interest formula, we get
I=. p r t
1,680=(3000)(r)(8). Multiplying
1,680= 24,000r Divide both sides by 24,000
0.07= r
So, the percentage is (0.07)(100)= 7%...