Question 1162673
<br>
I see your post got an empty response from another tutor.  That usually means that tutor started on a response and decided to quit.<br>
You will need to re-post.<br>
This sounds as if it could be an interesting problem.  However, the statement of the problem is grammatically incorrect; so we don't know what the problem really is.<br>
The information as given in your post says<br>
"... the sum of ...... is in the ratio (3n+8):(7n+15)..."<br>
That is mathematical nonsense: a sum is a single number, not a ratio.<br>
I suspect the ratio is to be between the sums of n terms of the two arithmetic progressions; but I'm not going to spend a lot of time working on a problem if I'm not sure what the question is.<br>
Please re-post stating the problem correctly.<br>