Question

A man invested Rs. 20000 at 10% per annum at simple interest, and another amount at 5% per annum at simple interest. At the end of the year he got 7% interest on the entire investment. Find out his total investment.
a. Rs. 20000
b. Rs. 30000
C. Rs. 40000
d. Rs. 50000​

Answer 1

Answer:

Let the amount invested be 5%p.a.

Then,

$\frac{20000 \times 10 \times 1}{100} + \frac{x \times 5 \times 1}{100} = \frac{(20000 + x) \times 7 \times 1}{100}$

$\small \implies \: 200000 + 20x = (20000 + x) \times 7 \\ \\ = 140000 + 7x \\ \\ \implies7x - 5x = 200000 - 140000 \\ \\ \implies2x = 60000 \\ \\ \therefore \: x = \frac{ { \cancel{60000}} \: \: ^{30000} }{ \cancel2} \\ \\ x = 30000$

Total amount invested = (20000+30000)=Rs 50000.

Additional information:-

• The most common is net income divided by the total cost of the investment, or ROI = Net income / Cost of investment x 100.
• Investment problems usually involve simple annual interest, using the interest formula I = Prt, where I stands for the interest on the original investment, P stands for the amount of the original investment 

Answer 2

Answer:

Helwo Santa sis

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A man invested Rs. 20000 at 10% per annum at simple interest, and another amount at 5% per annum at simple interest. At the end of the year he got 7% interest on the entire investment. Find out his total investment.

Step-by-step explanation: