I am not a student, not a homework. I got this in a test for job, hope someone can help with this
The first seven terms of an arithmetic progression are
$$7x+4, 9y, 7z+6, 4x+10, 3k, 3x+6, k+12.$$
The second, fifth and seventh terms of this progression form an infinite geometric progression. The sum of the terms of this geometric progression are?
Answer is $106$, I need to know HOW?
a. 180 b. 126 c. 106 d. 162