Question

The formula for the amount with simple interest is A = P(1 + rt). Find r, if A = 224, P = 200, and t = 2.

Answer 1

Solve for r:
Divide by P
A/P=1+rt
Subtract 1
\[\frac{A}{P}-1=rt\]
Divide by t.
\[\frac{(\frac{A}{P}-1)}{t}=r\]
Then just plug in the numbers and punch it in a calculator :P