“Can you smell the perfume in this room?” Abdul Malik Kadir said to a guy in a gray suit standing next to him. “My sinuses are cleared.” Kadir, 35, was sitting on a bench outside a ballroom at the Renaissance Washington hotel, surrounded by several hundred single Muslim men and women. The swelling crowd, ranging in age from 21 to 50-something, meant the evening of speed dating and socializing known as the Matrimonial Banquet was about to begin.