The interest rate would be 20%.
The formula is derived from the compound interest formula
.
We want to isolate r in this equation to rewrite the formula. The first thing we would cancel, outside parentheses, would be p; divide both sides by p and we have
We want to cancel the exponent, t, next. We can raise a power to its reciprocal to undo it; for example, raising a squared amount to the 1/2 power will undo the exponent. We will raise both sides of this to the 1/t power:
Now we cancel the 1 by subtracting, giving us
Using this formula, we plug in 3600 for A, 2500 for p and 2 for t:
The formula is derived from the compound interest formula
We want to isolate r in this equation to rewrite the formula. The first thing we would cancel, outside parentheses, would be p; divide both sides by p and we have
We want to cancel the exponent, t, next. We can raise a power to its reciprocal to undo it; for example, raising a squared amount to the 1/2 power will undo the exponent. We will raise both sides of this to the 1/t power:
Now we cancel the 1 by subtracting, giving us
Using this formula, we plug in 3600 for A, 2500 for p and 2 for t: