Not the cube, but the puzzle of
why I couldn't SOLVE the cube.
The Big Bang Theory Season 12, Episode 19
So, so, did we do it?
Did we just SOLVE string theory?
The Big Bang Theory Season 11, Episode 13
Excuse me, I thought we were
trying to SOLVE my problem.
The Big Bang Theory Season 6, Episode 18
"If interested, SOLVE the following
puzzles for a chance to meet him."
The Big Bang Theory Season 9, Episode 8
Solve for R.
The Big Bang Theory Season 2, Episode 1