Q)
(chatquestion)...999 1000
0-|1-2)"(3 4) (3 U)
10. (c)
. P 20
6. (c): 1, of 1, 8, 21, 40, 65, ....
,-1+7+13 + 19 + 25 +
Which represent the sum of r terms of an A.P. with fire
1 and common difference
is given by
%3D
1125
*******
. ar, ar, ar
to r terms
640=
12
term
=6.
G.P.
11. (c
1, = 12 x1+(r-1)6} = r(3r - 2)
10
.1, of given series:
r(3r-2) 3r-2 3(r-1)+
1-a
%3D
%3D
r-1
%3D
r-1
...
