A computer is available for Rs. 39000 cash or Rs. 17000 as cash down payment followed by five monthly installments of Rs. 4800 each. What is the rate of interest per annum under the installment plan?

Total Amount =39000

Paid amount =17000

Remaining Amount =22000

Installment for 5 months =5*4800 =24000

Extra Paymnet =24000-22000 =2000 (Simple Intrest)

Now Total Payment in one Month = 22000+17200+12400+7600+2800=62000( Princple for one month)

SI=P*R*T/100

2000=(62000*R*1/12)/100

R=38.70 =38.71% ANSWER

Total Amount =39000

Paid amount =17000

Remaining Amount =22000

Installment for 5 months =5*4800 =24000

Extra Paymnet =24000-22000 =2000 (Simple Intrest)

Now Total Payment in one Month = 22000+17200+12400+7600+2800=62000( Princple for one month)

SI=P*R*T/100

2000=(62000*R*1/12)/100

R=38.70 =38.71% ANSWER