Question

Find S infinity of a G.P whose 1st term is 28 and 4th term is 4/49 .

Answer 1

We have been given

a=28

t4=4/49

a.r^(4-1)=4/49

28.r^3=4/49

r^3=1/(49×7)

r=1/7

Sinfinity=a/(1-r)

=28×7/6=98/3