Question

The simple interest on a sum of money for 5 years is 3divided by 5
of the sum. Find the rate per cent per
annum.​

Answer 1

To find:-

• Rate percent per annum.

Assumption:-

Let the Sum of money be x

$\sf{Then\:SI = \dfrac{3}{5} \:of\:x = \dfrac{3x}{5}}$

Solution:-

We know,

$\sf{R = \dfrac{SI\times100}{P\times T}}$

= $\sf{R = \dfrac{3x\times 100}{x\times5\times5}}$

= $\sf{R = \dfrac{3\times100}{25}}$

= $\sf{R = 3\times 4}$

= $\sf{R = 12\%}$

$\sf{\therefore The\:Rate\:Percent\:Per\:annum\:is\:12\%}$

Note:-

• R = Rate
• T = Time
• P = Principal
• SI = Simple Interest

Some formulas:-

• $\sf{SI = \dfrac{P\times R\times T}{100}}$

• $\sf{T = \dfrac{SI\times100}{P\times R}}$

• $\sf{R = \dfrac{SI\times100}{P\times T}}$

• $\sf{P = \dfrac{SI\times100}{R\times T}}$