Question

Bo giner for a G.P ( rightarrow )
( a_{n}=128 Rightarrow a r^{n-1}=128 )
( a(2)^{n-1}=128 )
( frac{a_{2}^{n}}{2}=128 )
( 2^{n} a=256 )
( 2^{n}=frac{256}{a} )
( & )
( delta_{n}=255 )
( Rightarrow frac{aleft(x^{n}-1right)}{r-1}=255 )
( Rightarrow frac{aleft(2^{n}-1right)}{2-1}=255 )
( Rightarrow quad aleft(frac{256}{a}-1right)=255 quad(text { furm } 0 )
( Rightarrow )
( 256-a=255 )
( Rightarrow mid a=1 )
Hence of thin ( (A) ) is consect

# DREAMERS (1) JUQUUICUTROGRESSIUNE SINGLE CORRECT CHOICE TYPE The nth term of a GP is 128 and the sum of its n terms is 255. If its common ratio is 2 then its first term is - (B) 3 (C) 8 (D) None Deko Pages D-a (A) 1

Solution