S deposits a total of ₹50,000 in two accounts which give 8% and 12% simple interest annually, respectively. After one year, he gets a total ₹5,200. How much money does he deposit in the account with a 12% interest rate?

Interest rates: 8% and 12% annually.

Total interest earned after one year = ₹5,200. 

The formula for simple interest is:

Simple Interest = $$\frac{\text{Principal}\times \text{Rate} \times \text{ Time}}{100}$$   

Let the amount deposit be ₹x , ₹50000 - x .

According to the question, 

​$$\begin{aligned}&\frac{x \times 8 \times 1}{100} + \frac{(50000 -x) \times 12 \times 1}{100} = 5200 \\ \ \\ & 8x + 600000 - 12x = 520000 \\ & 4x = 600000 - 520000 \\& 4x = 80000 \\& x = \frac{80000}{4} = 20000 \end{aligned}$$ 

thus , the amount deposit at 12% is 50000 - 20000 = ₹30000.

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