The problem is as follows:
Marvin is the only son of Jennifer's grandfather, and Lindsey is the only daughter-in-law of Marvin's grandfather. If the only children of Jennifer are twins of 7 years of age and in this family it is true that from one generation to another consecutive 19 years have elapsed, what is the sum of the ages of the father and the great-grandfather of Jennifer?
The alternatives in my book are:
- $109$ years
- $135$ years
- $128$ years
- $116$ years
- $147$ years
Normally I would have tried to give an attempt to solve and show my progress but in this case I'm stuck at the very beginning hence I can't offer much other than what I'm already understanding which is described in the following lines.
I don't know if the way to go is to build up a single variable equation or is it a square one?.
The place where I'm stuck at is Lindsey, what kind of clue does she gives to the problem because I don't know how to relate it with the others.
Therefore, this problem has got me go around in circles for several days and I can't find how to get a clue where to begin. Can somebody help me to go in the right direction?.
It would help me the most if a suggested answer could include a visual aid to relate family ties. I mean how to tell in a tree where is the great grandfather, grandfather, son (husband) and daughter-in-law and grandchildren. To me this would greatly improve my understanding of this, since I'm lost at here where to tell the difference and understand how to make the math.