Toukir took a loan of Rs. 2400 with simple interest for as many year as the rate of interest. If he paid Rs. 864 as interest at the end of the loan period, What was the time period?

A 10 years

B 6 years

C 3 years

D 4 years

E None of these

Correct Answer: Option B

Let, rate of interest = r %

∴ Time period = r years.

⇒ Principal = 2400 rupees,

We know, that:

\(\Rightarrow {Simple\ interest = \frac{{Principal \times rate \times time}}{{100}}}\)

\(\eqalign{ & \Rightarrow 864 = \frac{{2400 \times r \times r}}{{100}} \cr & \Rightarrow {r^2} = 36 \cr & \Rightarrow r = 6 \cr}\)

Therefore time period \(r = 6\ years\) and rate of interest \(r = 6\%\)