A sum of Rs 8000 is divided into two parts. The simple interest on first part at the rate of 21% per annum is equal to the simple interest… — Answer & Discussion

A sum of Rs 8000 is divided into two parts. The simple interest on first part at the rate of 21% per annum is equal to the simple interest on second part at the rate of 35% per annum. What is the interest (in Rs) of each part?

A1050
B840
C1400
D1220

Answer not set

Join the discussion Report an error

Discussion 1

CCommunity03 Jun 2019

Let the two parts be ‘x’ and ‘(8000 – x)’

? Simple interest = (Principal × Rate × Time)/100

⇒ Simple interest on first part = (x × 21 × 1)/100 = 21x/100

⇒ Simple interest on second part = [(8000 – x) × 35 × 1]/100 = 2800 – 35x/100

But, the interest is equal in both cases,

⇒ 21x/100 = 2800 – 35x/100

⇒ 21x/100 + 35x/100 = 2800

⇒ 56x/100 = 2800

⇒ x = 100/56 × 2800 = Rs. 5000

∴ Interest on each part = 21x/100 = 21/100 × 5000 = Rs. 1050