Saved Bookmarks
| 1. |
wiil ternnn UIThe first term, common difference and last term of an an A.P are 12.6 and 252alsr ind the sum of all terms of this A.P. |
|
Answer» a= 12 , d= 6 , an= 252 an=a+(n-1)d or, 252= 12+(n-1)6 or, (n-1)6= 240 or, n-1 =40 so, n=41 Sn=n/2(a+an) S41=41/2(12+252) = 41*264/2 = 41*132 = 5412 |
|