(Q7).Explain why each of the lists above is a G.P.

(iv) 18, 16.2, 14.58, 13.122, …….

The given list forms a G.P.

Since each term, starting from the second can be obtained by its preceding term by a fixed number .

( r =
a2
a1
 =
a3
a2
 =
a4
a3
 = ......... = )