A sum of Rs.7000 is invested at a compound interest for three years, the rate of interest being 10% p.a., 20% p.a. and 25% p.a. for the 1st, 2nd and the 3rd years respectively. Find the interest received at the end of the three years.  Choose the correct answer:
A) A)282  B) B)4550  C) C)8383  D) D)8383  E) E)3284
Let A be the amount received at the end of the three years.   A = 7000[1 + 10/100][1 + 20/100][1 + 25/100]   A = 7000 * 1.65   A = Rs.11550   So the interest = 11550 - 7000 = Rs.4550   Answer: 4550
<result>B</result>
A sum of Rs.7000 is invested at a compound interest for three years, the rate of interest being 10% p.a., 20% p.a. and 25% p.a. for the 1st, 2nd and the 3rd years respectively. Find the interest received at the end of the three years.