The second term in a geometric sequence is 42.

8)   Let the first term  =  a

Then we know that the second term = ar = 42     where r is the common difference

And the sixth term  = 6302.625  = ar^5

So.....we have the following equations

ar  =  42

ar^5 = 6302.25          divide the ssecond equation by the first and we have

r^4 = 6302.625 / 42  

r = ( 6302.625  / 42 )^1/4  = 3.5

To find the first term we can solve this

ar = 42

a (3.5) = 42

a = 42/3.5  = 12  = first term

9)  Not as tough as 8

1st term = a  = 63      (1) 

4th term  = ar^3 = 122     (2)

Sub (1) into (2)

63r^3 = 122

r^3  = 122/63

r = (122/63)^(1/3)  ≈ 1.246 ≈  1.25