When the same constant is added to the numbers $60,$ $120,$ and $140,$ a three-term geometric sequence arises. What is the common ratio of the resulting sequence?
Let that constant be k.
(120+k)2=(60+k)(140+k)k2+240k+14400=k2+200k+840040k+6000=0k=−150
Common ratio = 120+k60+k=13
+900 
