Question

Petra invests $10,800. After 4 years she has earned $3240 in interest.
At what annual rate of interest did she invest her money?

Answer 1

Answer:

Rate =interest*100/principal*time

Rate = 7.5%

Step-by-step explanation:

Answer 2

At 7.5 % annual rate of interest did she invest her money.

What is rate of interest?

The percentage usually on an annual basis that is paid by the borrower to the lender for a loan of money is called rate of interest.

Given

Principal P = $10800

Time t = 4 years

I = 3240

Interest = $\frac{P\times r \times t}{100}$

$3240 = \frac{10800\times r \times 4}{100}$

$r= \frac{3240\times 100}{10800\times 4}$

r = 7.5 %

At 7.5 % annual rate of interest did she invest her money.

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