In what time will Rs. 64,000 amount to Rs. 68,921 at 5%

In what time will Rs. 64,000 amount to Rs. 68,921 at 5% per annum, interest being compounded half yearly ?

Interest is compounded half yearly ,
Here , Amount ( A ) = Rs. 68921 , P = Rs. 64,000

Time = T half–years , Rate =	5	% per half year
	2

A = P		1 +	R		^T
			100

⇒ 68921 = 64000		1 +	5		^T
			200

⇒	68921	=		1 +	1		^T
	64000				40

⇒	68921	=		41		^T
	64000			40

⇒		41		³	=		41		^T
		40					40

Equating powers on both sides , we get

⇒ T = 3 half years =	3	= 1	1	years
	2		2