Math Help Please?!?

Question

I need help with my homework please. i need help on finding the anwer
it says
FIND THE ANNUAL SIMPLE INTEREST RATE

#1 $103.50 interest on $2300 for 6 months
or
#2 $1600 interest on $8000 for 1 year

can someone please show me step by step on how to get the answer to one or both of these questions
please and thank you

Answer 1

The main formula for finding the amount of interest is
I=P*r*t,
where,I=Amount of Interest
P=principal Amount
r=rate of interest per year
t=time in years
Now by slightly adjusting this formula,you may find r
P*r*t=I
=> r=I/P*t
in your first problem
r=103.50/2000*1/2
=103.50/1000
=0.10350
multiply it by 100 to get the rate of interest in percent per year
therefore the rate =10.35% per year
#2 r=1600/8000*1
=0.20
Therefore,the rate of interest is 0.20*100 or 20% per year

Answer 2

Interest is the extra money gained on an investment or the extra money owed on a loan. The basic way used to find the amount of interest on an investment or a loan is the simple interest formula:

I = Prt

where I = interest, P = principal (the initial amount invested or borrowed), r = the rate of interest, and t = the amount of time (or the term) of the loan or investment. The rate of interest and the amount of time must have matching units. Usually an annual rate is given, thus the time must be in years.

Also from another source:

Answer 3

Principle x rate x time = interest
1.Principle (2300) x rate (r) x time (.5){half a year} = interest (103.5)
2300 x.5 = 1150. 1150r = 103.5 divide both sides by 1150 r = .09 or 9%
2. 8000(P) x r(rate) x 1(time, 1 year) =1600(interest)
8000r =1600 divide both sides by 8000. r = .2 or 20%