Question

A sum of money doubles itself in 8 years. what is the rate of interest?

Answer 1

Principal =Rs.x
Amount=Rs.2x
Time=8 years
Amount=Principal+Simple interest
2x=x+SI
2x-x=SI
SI=x
Simple interest=PTR/100
x=(x×8×R/100)
x=8xR/100
x×100/8x =R
R=100/8
R=12.5%
Hence Rate of interest=12.5%

Answer 2

Step-by-step explanation:

p=x

Amount=2x

t=8 yrs

amount=p+SI

2x=X+SI

SI=x

SI=ptr/100

x=(X*8*r/100)

X*100/8x=R

R=100/8

R=12.5

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