James borrows $4,200 to pay his college tuition. he signs a 5-year simple interest loan. lf the monthly payments are $78.40, what is the interest rate on the loan?

Since there are 12 months in a year you have to multiply it by your monthly payments which is 78.40
12×78.40=940.8
Since that is only a year payment you have to multiply it by your loan which is 5 years
940.8×5=4,704
So the loan is $4,704

4,704 I hope this really helps

The interest rate would be 2.4%.

We start out finding the total amount he pays, including interest. 

78.40/month * 12 months * 5 years = $4704

We take off the amount of principal:
4704-4200 = 504

This is the amount of interest he pays.  Now we use the simple interest formula, I=prt:

504=4200(r)(5)

Multiply 4200 and 5:
504=21000r

Divide both sides by 21000:
504/21000 = 21000r/21000
0.024 = r
2.4% = r