Girl with balloon should be accepted. I'd say it is the most common name for this piece (wikipedia agrees: https://en.wikipedia.org/wiki/Girl_with_Balloon )
Banksy's girl with balloon just got shredded...after selling for $1 million plus..and went up in value,....then some other idiot shredded his own Banksy and value went from $40K to zero !!!
I love that train painting, but couldn't have told you who made it or what it was called. That said, I'm pretty proud to be one of 9% who knew "Nude Descending a Staircase".
I guess I thought it was pretty straightforward, no arguments like with the geography one. So i missed you could name the work itself aswell..
I actually only got the painting by Raphael because I figured I would try the other ninja turtles.