Question

The first term common difference and last term of an ap is 12 6 and 252 . Find sum of all terms of ap

Answer 1

Step-by-step explanation:

An=a+(n-1)d

252=12+(n-1)6

252=12+6n-6

252=6+6n

252=6(1+n)

252/6=n+1

n+1=42

n=41

S41=41/2(12+252)

S41=41/2*264

S41=41*132

S41=5412