Question

Find the sum of the following AP (-5) , + ( -8 ) + (- 11 ) + ........ + (- 230 ) .
Please give complete solution of the answer

Answer 1

Answer:

-8930

Step-by-step explanation:

This is a decreasing AP

Initial term(a)= -5

∴The common difference(d)= -3, 'l' be the last term= -230

To find the no. of terms in an AP⇒ l=a+(n-1)d ⇒ n=(l-a/d)+1 ⇒ n=76

Sum of an AP is given by formula sum(S)=n/2(a+l)

                                                                  = -8930