# Math Help - Simple Interest

1. ## Simple Interest

An investment of $10 000 at 4% p.a. simple interest builds to$11 000. The number of months it takes to reach this amount is?

I was just wondering if the answer is 30 months.

2. If you were to demonstrate your calculation, I expect it would clear up your wondering.

Empirical Formula
I = Prt -- Right?

Given Information
I = 11000 - 10000 = 1000
P = 10000
r = 0.04

Algebra
t = I/(Pr) = 1000/(10000*0.04) = ??? years = ?? Months

3. It was just that this was a multiple choice question with the options:

(A) 330
(B) 27.5
(c) 273
(D) 23

But no matter how many times I worked out the question using SI = Prt, it worked out to be 30, so I just wanted to make sure I wasn't getting dumber.