The act of solving a problem.
Season 3, Episode 4 - The Pirate Solution
Aired October 12, 2009
When Raj faces the threat of deportation if he doesn't find a job, he must turn to Sheldon for help, but can he handle working for his friend? Meanwhile, Leonard and Penny are enjoying life as a couple, except for their third wheel - Howard.
Season 5, Episode 16 - The Vacation Solution
Aired February 9, 2012
After Sheldon's boss forces him to use his mandatory vacation time, he decides to work at Amy's lab and puts his relationship to the test when it appears he may be bad at biology. Meanwhile, Howard and Bernadette hit a pre-marital snag when Bernadette's father insists they sign a pre-nuptial agreement.
Season 8, Episode 2 - The Junior Professor Solution
Aired September 22, 2014
After the university finds a way for Sheldon to change his field of research, he is promoted to a Junior Professor and must teach a class. When nobody signs up for Sheldon's class, Howard surprisingly enlists. Meanwhile, Amy plays Penny and Bernadette against each other as tensions rise over Penny's new job at Bernadette's company.
Season 9, Episode 23 - The Line Substitution Solution
Aired May 5, 2016
Sheldon hires Stuart to spend the day with Amy when he'd rather go to a movie screening. Also, Leonard's mother, Beverly, comes to town and Penny struggles to make a connection with her.