Question

If a certain sum becomes 4 times it self in 16 years ,then the rate of interest is

Answer 1

Let Sum be=x

Time Given=16 years

Question asking a sum become 4x in 16 years if the sum is x

Amount after 16 years=4x

Sum=x

SI=Amount-Principal(sum)

SI=4x-x

SI=3x

Now we got

Principal=x

Time=16 years

Rate=r

SI=3x

we know,

SI=Principal*Rate*time/100

3x=x*r*16/100

r=3x*100/16x

r=300x/16x

x will be cancelled out

r=300/16

• r=18 $\frac{3}{4}$ percent

Rate=18 $\frac{3}{4}$ percent