Question
A man invested certain sum at simple interest of r% p.a.
such that it amounts to 130% of itself in 3 years. Find the interest earned when Rs. 3000 is invested at simple interest of r% p.a. for 3 years.Solution
Let the sum invested be Rs. ‘P’ Therefore, interest earned in 3 years = 1.3P – P = Rs. 0.3P ATQ; 0.3P = (P × r × 3) ÷ 100 Or, r = 30 ÷ 3 Or, r = 10 So, required interest earned = (3000 × 10 × 3) ÷ 100 = Rs. 900
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