A sum of Rs.4000 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.
Pick.
A) 2888 B) 3120 C) 2877 D) 2600 E) 1277
Let A be the amount received at the end of the three years.   A = 4000[1 + 10/100][1 + 20/100][1 + 25/100]   A = (4000 * 11 * 6 * 5)/(10 * 5 * 4)   A = Rs.6600   So the interest = 6600 - 4000 = Rs.2600   Answer: 2600
<result>D</result>
A sum of Rs.4000 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.