Question

find the sum of first 50 terms of the 1/2 1/4 1/8​

Answer 1

Answer:

a2=14, a3=18

a+2d=14-----(1)

a+2d=18-----(2)

Subtract equation (1) and (2)

Therefore d=2

Since, a+d=14 , a+4=14.

Therefore, a=10

Therefore, Sn=n/2[2a+(n-1)d]

S15=50/2[2x10+(5-1)x4]

=50/2(20+200)

=50/2x220

=5500