Just to add my two cents to the language contest side discussion.
Do not think of how the languages were internally designed, think of "what" they are used for and "why" the companies made such a choice.
C:
Embedded programming
Device drivers and kernels
Game Programming (yes, still used but not as much nowadays)
Operating Systems (UNIX anyone)?
Teaching tool in some colleges around the world
Core compiler language for other languages due to the low level features
C++:
Major video game Engine development language (not so much the actual game logic due to scripting)
High level back-end development of websites (Facebook, Google)
Desktop application development (Java/C# seem to overtaking this)
Almost all commercial business applications are heavily coded in C++ (Adobe, Microsoft and most Professional audio software are written exclusively in C++)
Higher level Operating System development
I could go on and on but you get the picture. The test case here is not really about speed, but the language being efficient and the right tool for the job. Would you want to code an entire OS in C++? No. Not because C++ is not capable because with the right development and algorithm in certainly can be done. C has been used for this due to low-level abstractions it allows. On the other hand, I would never use C to code the latest Xbox One game. C "can" be used for this, but again, C++ has been proven to work extremely well with the Game Engine rendering and psychics. Also, Lua is a major scripting language that C++ sits better with. If I threw a toolbox in languages in front of you and asked you to build the next leading enterprise software package - would you choose C or C++? Or Java or even Python? Yes, it's cliche' I know, but it's all about the right tool for the job. Speed only really comes into the equation when people begin looking at bottlenecks in their code. Can a function be executed faster if it was "inline" for example?
Just my two cents.
Ada x