Question

A sum of money becomes double in 20 years at simple interest. In how many years will it be triple?

Answer 1

Assume x is the initial amount,

x become 2x in 20 years (simple interest =x),

x become 3x in n years (simple interest =2x),

Let the amount be x which becomes 2x in 20 years

simple interest in 20 years = 2x - x = x

Time, T = 20 years

I

=

PRT

100

x

=

x R × 20

100

I=PRT/100x=x/ R × 20100

R = 5%

Let the amount x becomes 3x in n years

Interest = 3x - x = 2x

Rate of interest,R = 5%

n

=

100

×

SI

PR

=

100

×

2

x

x

×

5

=

40

n=100×SIPR=100×2xx×5=40

Amount gets triple in 40 years

Hope this helps.... Mate

Answer 2

Answer:

40 will be the answer...