Question

Suresh took loan of some amount that becomes rs 2520 in 2 years and rs 2700 in 5 years on simple interest.Find out the intresrt rate

Answer 1

Let "I" be interest on a principal "P" for time "T" at "R %" per annum. Also, let "A'' be the amount.

Then, the formulas, you should know are as follows :

✒️ I = (PRT)/100

✒️ A = P + I

✒️ P = (I×100)/(R×T)

✒️ R = (I × 100)/(P×T)

✒️ T = (I × 100)/(P × R)

______________________________

$\bold{\huge{SOLUTION\: :}}$

Principal = P (say)

Then, Subtracting these two equations, we will get :

P + Int. for 5 years = ₹ 2700

P + Int. for 2 years = ₹ 2520

______________________________

Int. for 3 years = ₹ 180

Int. for 2 years = ₹ {(180/3)×2} = ₹120

So, P + Int. for 2 years = ₹ 2520

=> P = ₹ (2520 - 120)

=> P = ₹ 2400

So, rate of interest = (I×100)/(P×T)

= (120 × 100)/(2400×2)

= 2.5 % [REQUIRED ANSWER]