When principal = ₹ S, rate of interest = 2r % p.a, then

When principal = ₹ S, rate of interest = 2r % p.a, then a person will get after 3 years at compound interest

Here , Amount ( A ) = ? , Principal (P) = ₹ S , Rate ( R ) = 2r% per annum , Time = 3 years
As we know that ,

∴ Amount = P		1 +	R		^T
			100

Amount = S		1 +	2r		³	= S		1 +	r		³
			100						50