Question

Find the interest rate r when p = 800, a = 2700, and t = 3.​

Answer 1

For compound interest, 50%.

Explanation:

(I'm assuming this question is asking for the compound interest):

The formula for compound interest is given by:

`A=P(1+(r)/(n))^(nt)`

Plug in the values we know. We can use 1 for n:

`2700=800(1+r)^3\\27/8=(1+r)^3\\1+r=\sqrt[3]{27/8}\\r=3/2-1\\r=1/2=.5`

So, the interest rate is 50%.

Answer 2

r = 0.5 or 1/2

Explanation:

Simple Interest Rate Formula: A = P(1 + r)^t

Simply plug in our known variables:

2700 = 800(1 + r)³

Now we solve for r:

Divide both sides by 800

27/8 = (1 + r)³

Take the cube root on both sides

∛27/8 = ∛(1 + r)³

Simplify

3/2 = 1 + r

Subtract 1 on both sides

r = 1/2

r = 0.5