Question

If a sum of money at simple interest doubles in 5 years, it will become 4times in​

Answer 1

Answer:

1/5 = 3/x

x = 15 years (Ans)

(Mark as brainlist)

Answer 2

Answer:

if Principle amount is P

rate of interest is R

time is 5 years

Simple interest =

PRT/100

PR5/100

now, the amount become double in five years that means P + PR5/100 = 2P

100P+PR5 = 200P

PR5 = 100P

R = 100P/5P

=20

It means the principal amount become double in 5 years with 20% rate of interest

now

4P = P20T/100 +P

400P= 20PT + 100 P

300P = 20PT

T = 300P/20P

T = 15 years

so it means the amount will become four times in 15 years