Question

a sum of money become 2.5 time after a certain rate of interest per annum than how much will be the money become after 18 yr​

Answer 1

Answer:

Let the sum of money be

′

x

′

.

T=2 years

C.I=2700. , Rate=R

A=P(1+

100

R

)

2

⇒

(x+2700)=x(1+

100

R

)

2

⟶(I)

Now,

S.I=2500

⇒2500=

100

x×R×2

⇒

xR=125000

⇒

R=

x

125000

→(II)

Putting

′

x

′

in eq (I)

(

R

125000

+2700)=

R

125000

(1+

100

R

)

2

⇒(

R

125000+2700R

)=

R

125000

(1+

100

R

)

2

⇒(125000+2700R)=125000(1+

100

R

)

2

⇒1250+27R=1250(1+

100

R

)

2

⇒1250+27R=1250(1+2(0.0R)+(0.0R)

2

)

⇒1250+27R=1250+25R+0.125R

2

⇒0.125R

2

−2R=0

⇒R(0.125R−2)=0

⇒R=0 or 0.125R−2=0

But R can't be 0.

∴0.125R−2=0

⇒R=

0.125

2

=16

∴

R=16%

Step-by-step explanation:

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