Read this: Roughly 70% of the area in the RSFSR consisted of broad plains, with mountainous tundra regions mainly concentrated in the east. The area is rich in mineral resources, including petroleum, natural gas, and iron ore.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): What percentage of the RSFSR wasn't made up of plains?
unanswerable