Question

At what rate percent CI does a sum of money become nine fold in 2 years?
a)100%p.a
b)200%p.a
c)300%p.a
d)400%p.a

Answer 1

200percent p. a I hop this answer help you

Answer 2

ANSWER

Find out the at what rate percent CI does a sum of money become nine fold in 2 years .

To proof

Formula

$Compound\ interest = P(1+\frac{r}{100}})^{t}$

where

P = principle

r = rates

t = time period in years

As given

sum of money become nine fold in 2 years

intial principle = P

after 2 years

compound interest = 9P

Put the values in the equation

$9P = P ( 1 + \frac{r}{100})^{2}$

$9 = (1+\frac{r}{100} )^{2}\\3^{2}= (1+\frac{r}{100} )^{2}\\3-1 = \frac{r}{100}$

200% = r

hence option b)200%p.a is correct

Hence proved