simple interest (need full details)?

Question

calculate the simple interest paid and the current amount in the account for $6390 for 170 d at 5 1/4%
1. I=
2. A=

Answer 1

For simple interest you just have to find out what part
of the whole year 170 days is and multiply times the
total annual interest 170/365 = 2.44521%

Day-Principal-Interest- Total Interest -New Principal
1- $6,390.00 -2.44521%- $156.25 - $6,546.25

Answer 2

The formula is Interest = Principle X Rate X Time
In your case I = 6390 X .0525 X (170/365) = 156.25.

The current amount in the account is the original principle plus the interest, so 6390 + 156.25 = 6546.25

Answer 3

There is a website that calculates math problems and then explains how to do them. It is www.webmath.com. I think it is a handy site to know.