People of German origin are found in various places around the globe. United States is home to approximately 50 million German Americans or one third of the German diaspora, making it the largest centre of German-descended people outside Germany. Brazil is the second largest with 5 million people claiming German ancestry. Other significant centres are Canada, Argentina, South Africa and France each accounting for at least 1 million. While the exact number of German-descended people is difficult to calculate, the available data makes it safe to claim the number is exceeding 100 million people.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many people in the world have German heritage?
Ah, so.. 100 million

The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a top-contact fourth rail is located centrally between the running rails at −210v DC, which combine to provide a traction voltage of 630v DC. London Underground is now upgrading its fourth rail system to 750v DC with a positive conductor rail energised to +500v DC and a negative conductor rail energised to -250v DC. However, many older sections in tunnels are still energised to 630v DC. The same system was used for Milan's earliest underground line, Milan Metro's line 1, whose more recent lines use an overhead catenary or a third rail.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Many newer sections in tunnels are energised to what voltage?
Ah, so.. unanswerable

The use of time is an important issue in understanding human behavior, education, and travel behavior. Time-use research is a developing field of study. The question concerns how time is allocated across a number of activities (such as time spent at home, at work, shopping, etc.). Time use changes with technology, as the television or the Internet created new opportunities to use time in different ways. However, some aspects of time use are relatively stable over long periods of time, such as the amount of time spent traveling to work, which despite major changes in transport, has been observed to be about 20–30 minutes one-way for a large number of cities over a long period.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): The use of time is important in understanding what?
Ah, so..
human behavior, education, and travel behavior