A sum of Rs.4800 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 choice from the following:
A) 2777
B) 3120
C) 6877
D) 1699
E) 1667
Let A be the amount received at the end of the three years.   A = 4800[1 + 10/100][1 + 20/100][1 + 25/100]   A = (4800 * 11 * 6 * 5)/(10 * 5 * 4)   A = Rs.7920   So the interest = 7920 - 4800 = Rs.3120   Answer: 3120
<result>B</result>
A sum of Rs.4800 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.