ques is as follows

Dear Student

He Paid  60,000 Rs

Balance amount is 60000

At the end of the first month He ahs to pay 

5000+ 12% interest on (12X 5000)

At the end if secind month  5000+ 12% interest on (11X 5000)

Similarly at the end of n the month

=5000+ 12% interest on (nX 5000)=5000(1+     12n/100 ) =50(100+12n)=5000+600n

Aum over all n values from n=1 to 12

Total paid install met amount=  Aigma ( 5000+600n)=  (12X5000)  + 600(1+2+...12) =60,000+600X78=1,06,800

Total ost of shop= 60000+1,06,800 =1,66,800.Rs

Regards

Team

Topperlearning