Question

given n=12,l=71,d=3in an A.P find a and s​

Answer 1

Answer:

37=a+3(12−1)=a+33

⇒a=37−33=4

S

12

=

2

12

(4+37)=246

Answer 2

Answer:

I solved it..incase any doubts .. Comment'on it ...or else if any method if you know please share .. or if it is wrong please correct it ....

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