If the difference between compound interest (interest compounded yearly) and simple interest on a certain sum at the rate 20% p.a. after 3 years is Rs.1280 then what is the principal?
Select:
A) 7900  B) 8,000  C) 10,000  D) 8,300  E) 9,300
let p is the principal,so p([120/100]^3-1)-p*20/100*3=1280   p[728/1000-3/5]=1280   p=1280*5*1000/728*5-3000=10000   ANSWER:10,000
<result>C</result>
If the difference between compound interest (interest compounded yearly) and simple interest on a certain sum at the rate 20% p.a. after 3 years is Rs.1280 then what is the principal?