# Thread: Compound interest!

1. ## Compound interest!

A company invests $5000, some into an account paying 5.2% simple interest and the remainder in an account paying 4.5% simple interest per annum. After 2 years the$50000 had grown to $54976. How much went into each account? 2. Originally Posted by niruja A company invests$50000, some into an account paying 5.2% simple interest and the remainder in an account paying 4.5% simple interest per annum. After 2 years the $50000 had grown to$54976. How much went into each account?
At time zero, you have: $\displaystyle (x+y)*50000$

Where $\displaystyle x + y =1$ as they are percents of the principal that is invested. We'll say x% earns 5.2% simple interest.

After two years we should have:

$\displaystyle x*50000*(1+2*.052) + y*50000*(1+2*.045) = 54976$

Dividing by 50000 gives us:

$\displaystyle 1.104x + 1.09y = 1.09952$

We also know that $\displaystyle x + y =1$, so now we have two equations with two unknown variables. I believe you can now solve for x and y.