Question

A certain sum of money at simple interest triples itself in 8 years in how many years it will be five times

Answer 1

Hi ,

Let the principal = Rs x

Time = t = 8 years

Amount ( A ) = Rs 3x

Simple interest = A - P

S.I = 3x - 2x = x

Let the rate of interest = r

r = ( S.I × 100 )/pt

r = ( x × 100 )/( x × 8 )

r = 25/2%

2 ) Principal = p = Rs x

r = 25/2%

A = Rs 5x

Let time = T years

S.I = A - P

= 5x - x

= Rs 4x

Now ,

T = ( S.I × 100 )/pr

= ( 4x × 100 )/ ( x × 25/2 )

= ( 4 × 2 × 100 )/25

= 32

T = 32 years

I hope this helps you.

: )