Question

Which of the following statements is INCORRECT?

• A. If are the sum of first natural numbers, their squares and their cubes, respectively, then .
• B. A farmer buys a used tractor for . He pays cash and agrees to pay the balance in annual installments of plus interest on the unpaid amount. The tractor will cost him for .
• C. If the and terms of a . are and respectively, then its term is .
• D. None of these

Answer 1

Answer: (A)

(a) If are the sum of first natural numbers, their squares and their cubes respectively, then
,


Now,





(b) Farmer purchased a tractor for . After paying , he will left with .
interest paid
interest paid

interest paid
Total amount of interest

The cost of tractor .


and

On dividing by , we get



Putting the value of in , we get


term,
[using and ]