I agreed to lend a friend money at a special interest rate of 10% per year on the condition that the friend borrow enough that they would pay %650 in interest over a period of 4 years what is the minimum amount my friend could borrow

thats $650 dollars not percent

I = PRT

650 = P * 0.1 * 4

650 = 0.4P

650 / 0.4 = P

1,625 = P

To find the minimum amount that your friend could borrow, we need to calculate the initial principal loan amount.

We can approach this problem by using the formula for simple interest:

Interest = Principal x Rate x Time

In this case, we know the interest is $650, the rate is 10% per year, and the time is 4 years. Let's plug those values into the formula and solve for the principal loan amount:

$650 = Principal x 0.10 x 4

Simplifying the equation:

$650 = 0.4 x Principal

To solve for the principal loan amount, we divide both sides of the equation by 0.4:

Principal = $650 / 0.4
Principal = $1625

Therefore, the minimum amount your friend could borrow is $1625.