Question

A sum of money invested at simple interest triples itself in 8 years . Find in how many years will it become 8 times at the same rate of interest

Answer 1

Step-by-step explanation:

let p = p

A = 3p

si = 3p-p = 2p

t = 8yr

$r = \frac{si \times 100}{pt} \\ = \frac{2p \times 100}{p \times 8} \\ = 25 \%$

A = 8p

si = 8p-p = 7p

r = 25%

$t = \frac{si \times 100}{pr} \\ = \frac{7p \times 100}{p \times 25} \\ = 28 \: yr$