Question

Rs.12000 invested at 10% Simple Interest and another investment at 20% Simple Interest together give a 14% income on the total investment in one year. Find the total investment.

• A. Rs.8000
• B. Rs.18000
• C. Rs.24000
• D. Rs.20000

Answer 1

Answer:

D. Rs.20000

Here's how to solve this problem:

1. Define Variables:

• Let the investment at 10% be Rs. 12000

• Let the other investment at 20% be Rs. x

• Total investment = Rs. (12000 + x)

2. Calculate Interest from Each Investment:

• Interest from 10% investment = (12000 10 1) / 100 = Rs. 1200

• Interest from 20% investment = (x 20 1) / 100 = Rs. x/5

3. Calculate Total Interest:

• Total interest = Interest from 10% investment + Interest from 20% investment

• Total interest = 1200 + x/5

4. Calculate Total Interest Based on 14% Income:

• Total interest = (Total investment 14 1) / 100

• Total interest = ((12000 + x) * 14) / 100

5. Set Up the Equation:

• Equate the total interest from step 3 and step 4:

  • 1200 + x/5 = ((12000 + x) * 14) / 100

6. Solve for x:

• Multiply both sides by 100:

  • 120000 + 20x = 14(12000 + x)

  • 120000 + 20x = 168000 + 14x

  • 20x - 14x = 168000 - 120000

  • 6x = 48000

  • x = 8000

7. Calculate the Total Investment:

• Total investment = 12000 + x

• Total investment = 12000 + 8000 = Rs. 20000

Therefore, the total investment is Rs. 20000.