Question

The formula for determining simple interest is i = prt, where

i is the interest
p is the principal
r is the interest rate as a decimal. For example, if the interest rate is 3%, then r = 0.03.
t is the time
Units must be consistent. If the unit for p is dollars, the unit for i is dollars and the unit for t is years, what
must the units for r be?
dollars/year
Solve this formula for r.
i
pt
r =
6000 dollars are invested at a simple interest rate of 2 percent for 5 years. How much interest is earned, to
the nearest cent?
dollars.
What is the interest rate, as a percent, that is necessary to earn 100 dollars in simple interest if 5000
dollars are invested for 5 years, to 1 decimal place?
%/year.
Question Help: Message instructor

Answer 1

0.4%

Explanation:

well

i is your goal, which is 100 dollars

p is principal, which is 5000 dollars

r is rate, which is unknown

t is time, which is 5 years

so with the formula i = prt

100 = 5000 r 5

100/25000 = r

1/250 = r

r = 0.004 or 0.4%