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?

a. 7900
b. 8,000
c. 10,000
d. 8,300

• 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
• 8 years agoHelpfull: Yes(2) No(1)
• question will be what is sum
  then its 10000
• 8 years agoHelpfull: Yes(1) No(7)