X took a loan of ₹5000 on simple interest, the rate of interest being the same as the number of years for which the loan was taken. If the interest paid was ₹1800, then what was the rate of interest?

X took a loan of ₹5000 on simple interest, the rate of interest being the same as the number of years for which the loan was taken.

Let's assume the number of years and the rate of interest is T and R respectively.

T = R

If the interest paid was ₹1800.

$$interest\ =\ \frac{P\times\ R\times\ T}{100}$$

$$1800=\frac{5000\times\ R\times\ R}{100}$$

$$1800=50\times R^2$$

$$36=R^2$$

$$6^2=R^2$$

Rate of interest = R = 6%