Determine the first three terms of geometric progression of which:
The 7th term is 192 and the 2nd term is 6
r^5 = 192 / 6 = 32 ... r = 2
terms ... 6/2 , 6 , 6*2
the terms are 5 apart, so
r^5 = 192/6 = 32
r = 2
Now I expect you can finish it off.
Post your work if you get stuck