Question:
The third term of a G.P. is 4, the product of the first five terms is ____________.
Solution:
Given third term of G.P is 4
Let a be the first term of G.P and r denote the common ratio.
Then second term is ar
Third term is ar2
fourth term is ar3 and fifth term is ar4 .
Since ar2 = 4
Product of first 5 terms is a. ar. ar2 ar3 ar4
= a5 r10
= (ar2)5
Hence, product of first 5 terms = 45