Question

Ramesh invests two sum of money X and Y at the rate of 10% per annum and second is 20% per annum at Compound interest for 2 years.The total interest on the both sum of money is Rs. 5350 then find the sum of money invested in X if the total sum of money X and Y was Rs. 20,000?
1. Rs. 15000
2. Rs. 10000
3. Rs. 12000
4. Rs. 14000

Answer 1

Correct Answer - Option 1 : Rs. 15000

Given

First rate of interest = 10%

Second rate of interest = 20%

Time period = 2 years

Calculation

⇒ By mixture and allegation

⇒ At 10% Compound interest for 2 years = 21%

⇒ At 20% Compound interest for 2 years = 44%

⇒ Mean rate = (5350/20000) × 100% = 107/4%

X                      Y

21%               44%

       (107/4)%

3                    1 → (Ratio of principal)

⇒ Principal of X = (3/4) × 20000 = Rs. 15000