Question

In four numbers, first three are in GP and last three are in AP whose common difference is 6. If the first and last numbers are the same, then the first number will be

(A)  2 

(B)  4 

(C)  6 

(D)  8

Answer 1

Correct option (D) 8

Let the numbers be

a/r,a,ar,2ar - a    .....(1)

where first three numbers are in GP and last three are in AP. Given that the common difference of AP is 6, so

 ar - a = 6  .....(2)

Also given

From Eq. (1) we get

Required numbers from Eq. (1) are 8,-4, 2 ,8