Question

In what time money will become 3 times if simple interest is 10%

Answer 1

There is a simple and sweet formula to solve this problem.
(n - 1) x 100 = rt
n = Number of times the amount will become in tyears at r% per annum SIMPLE INTEREST.
Apply to given problem :-
n = 3, r = 10, t = ?
( 3 - 1 ) x 100 = 10 x t
t = 200/10 = 20 Years
Cheers !!!!!!
NOTE : This relation holds good only for SIMPLE INTEREST.
****** Conventional method *********
Let the number of years required = t
Let Principle = P
Amount = 3P
Interest earned = 3P - P = 2P
Now using formula SI = PRT/100, we have
2P = P x 10 x t/100
2 = 10 x t/100
t = 200/10 = 20 years
Cheers !!!!