Mean of the first n terms of the A.P. a + ( a + d ) + ( a + 2d ) + ………is
A. a+nd/2
B. a + ( n – 1 )d
C. a+(n−1)d/2
D. a + nd
Answer:A
Mean of the first n terms of the A.P. a + ( a + d ) + ( a + 2d ) + ………is
A. a+nd/2 B. a + ( n – 1 )d C. a+(n−1)d/2 D. a + nd