Question

Maria has a savings account that is earning simple interest. If she started with $200 in the account and has earned a total of $8 in interest in two years, what is the rate of the account? Use the formula .

Answer 1

We are going to use the interest formula again for this question too!

SI = P x R x T

Our principle is $200, total is $8, and time is 2. Let's plus this into the equation and solve:

8 = 200(2r)

Do you know how to solve for r to get our answer?

Answer 2

no

Answer 3

im only a seventh grader

Answer 4

That's okay! So we solve this equation by using PEMDAS but in reverse, to isolate the r onto one side of the equation.

To start with this, we need to divide 200 on both sides

8/200 = 200(2r)/200

What is 8/200?

Answer 5

And oh interesting, I am surprised you are learning this in 7th grade!

Answer 6

0.04

Answer 7

did he leave

Answer 8

Yep! So now we have

0.04 = 2r

Do you know what we do next to solve for r?

Answer 9

no

Answer 10

im sorry

Answer 11

:(

Answer 12

You're okay! We have to divide 2 on both sides of the equation.

So 0.04/2 = 2r/2

What is 0.04/2? that will be our answer. Also, were you ever taught PEMDAS? it seems weird that you're learning interest so early!

Answer 13

yes but doing it with terms are hard

Answer 14

0.02

Answer 15

Correct! So the interest rate is 0.02 or 2%

Answer 16

oh thankyou.