Question

The simple interest and compound interest on a certain sum of money for 2 years are rs.8000 and rs.8800 respectively.find the sum and rate% per annum ?

Answer 1

S.I=P*R*T/100₉
8,000=P*R*2/100
8,000*100/2=P*R
P*R=4,00,000             ........(i)


C.I=P(1+R/100)²  -P
⇒8,800=P((100+R)/100)²  -P
⇒8,800 = P((100+R)²/10,000) - P
⇒8,800 = {P(100+R)² - 10,000P)/10,000
⇒8,800*10,000 = P(10,000+R² + 200R) - 10,000P           [(a+b)² = a² + b² + 2ab]
⇒8,800*10,000 = 10,000P + PR² + 200PR -10,000P
⇒8,800*10,000 = PR²+200PR
Substituting value of P*R,
⇒8,800*10,000 = 4,00,000R+8,00,00,000
⇒8,80,00,000-8,00,00,000 = 4,00,000R
⇒80,00,000 = 4,00,000R
⇒R = 80,00,000/4,00,000
⇒R = 20%
⇒P = Rs. 20,000


HOPING THAT IT WILL HELP YOU!!!