Question

find the sum of 10 terms of g.p 1,4,16,64​

Answer 1

Step-by-step explanation:

Sn= a( r^2 -1 )/r -1. when r>1

here

a=1

r= 4/1=4

therefore

S10 = a( r^10 -1 ) /r -1

S10 = 1( 4^10 -1 ) /4 -1

=1 x 1048576 -1 / 3

= 1048575/3

= 349525

therefore S10=349525

thanks