Q14 of 110 Page 53

A sum of ₹1000 is deposited every year at 8% simple interest. Calculate the interest at the end of each year. Do these interest amounts form an A.P.? If so, find the total interest at the end of 30 years.


Simple interest = P* R * T /100

P = ₹1000


R = 8


T = 1


Simple interest = 1000*8*1/100 = 80


Interest at the end of first year = ₹80


For second year,


P = 1000 + 1000 = 2000


R = 8


T = 1


Simple interest = 2000*8*1/100 = 160


Interest at the end of second year = ₹160


Similarly, for third year, P = 1000 + 1000 + 1000 = 3000


SI = 240.


Yes the simple interests form an A.P.


a = 80


d = 160–80 = 80


n = 30


Sum of terms =


⇒ Sum of terms =


⇒ Sum of terms =


⇒ Sum of terms = 37200


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