Kirsch auditorium was packed for the 100K Pitch Contest Finals. Twelve teams had 60 seconds each to pitch their ideas. More audience members watched real-time streaming from a separate room.

The 48th Head of the Charles Regatta, the world’s largest two-day rowing event, occurred this past weekend. MIT, which is ranked Division 1 in crew, had teams competing in events throughout the weekend. Here, the MIT men’s lightweight crew team warms up in preparation for a race early Sunday evening.

Kevin Marume (center) and other brothers from PKT dance to a theme about becoming a man. Their choreography included songs such as “I’ll Make a Man Out of You” from Mulan and “Sexy and I Know It” by LMFAO. The event, held Sunday evening in Kresge, featured dancing, singing, and comedies performed by fraternities and sororities.

On Sunday, there was a campus-wide flashmob modeled after the popular song “Gangnam Style” with Richard Yoon ’13 acting as PSY, the artist behind the Korean hit.

Hundreds gathered for the 3rd annual East Cambridge Ribfest last Sunday on Fulkerson Street. $2 ribs from some of Cambridge’s best, including the East Side Bar, Midwest Grill, and Redbones.