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To find:-
n
Solution:-
Sn =860
T1 = 2
Tn = 41 , Tn = [a +( n-1 )d ]
n =?
SN = n/2 (2a + {n-1}d ) = 860
n/2( 2× 2+ (n-1)d ) = 860
n/2 (tn+t1) = 860
n/2 (41 +2) = 860
n/2 (43) = 860
n = (860 ×2 )/43
n = 40
Hope it helps you!!