Question

The 4th ,6th and the last term of a geometric progress are 10 ,40 and 640 respectively. If the common ratio is positive find the first term common ratio number term of the series

Answer 1

Answer:

the common ratio will be +2.

first term would be 1.25

number of terms will be 10

Step-by-step explanation:

fourth term= ar³=10

sixth term= ar⁵=40

nth term=ar^(n-1)

therefore common ratio r= 2

put this in first eqn

therefore first term a=1.25

putting these in 3rd eqn

n-1=9

=> n= 10

therefore number of terms is 10.

do follow...