Question

find the sum of A.P. 1/15 , 1/12, 1/10 ....to 11 term

Answer 1

1. 1 1 5+4. 3
a = ''''' , d = """ + """ = """"""= """"" , n = 11
15. 12. 15. 60. 20

11. ( 1. 3. )
S= """" ( 2 ×""" +(10× """"") )
2. ( 15. 20. )

11. ( 2. 3. )
= """" ( """" + """" )
2 ( 15. 2. )

11. 49. 539
= """ × """" = """"
2 30. 60