Question

Raman deposits a certain sum of money each month is a recurring deposit account of a bank if the rate of interest is 9 whole 1/2% per annum and Raman gets 78,638 from the bank after 3 whole 1/2% years find the value of monthly installment

Answer 1

Answer:

1600

Step-by-step explanation:

Given, r = 9 1/2% p.a. = 9.5%

          A = ₹ 78638

           n  = 3 1/2 years = 42 months

Let Monthly Installment be P

∵ A = Pn + (P*n(n+1)*r)/2400

⇒ 78638 = P * 42 + (P * 42 * 43 * 9.5)/2400

⇒ 78638 = 42P + (P * 42 * 43 * 19/2)/2400

⇒ 78638 = 42P + (P * 21 * 43 * 19)/2400

⇒ 78638 = 42P + (P * 7 * 43 * 19)/800     (Dividing 21 and 2400 by 3)

⇒ 78638 * 800 = 800(42P + 5719P/800)    (Multiplying both sides by 800)

⇒ 78638 * 800 = 33600P + 5719P

⇒ 78638 * 800 = 39319P

⇒ P = 78638 * 800 / 39319 = ₹ 1600