I used A=P(1+r/n)^nt to solve but I've gotten it wrong

Question

$20,000 is loaned at a simple interest rate of 8% for 90 days.

Answer 1

Simple Interest Formula 

Simple Interest = Principal × Interest Rate × Time

Interest = I

Principal (initial value) = P

Interest rate = r

time = t (always in years)

I = P * r * t

I = 20000 * 0.08 * 0.246575

I = 394.52

Answer 2

The formula you used is for compound interest.

The problem states simple interest.

A = 20000(1 + 0.08)