To mix a punch, yvonne begins with 4 liters of ginger ale and adds 2,650 milliliters of cranberry juice. about how many 200-ml glasses of punch can be served?

Since Yvonne mixed 4 liters (that's 4000 milliliters) of ginger ale with 2650 (I'm assuming the comma separates the thousands) milliliters of cranberry juice, then she'll have a total of 4000+2650=6650 mL of punch.
Dividing that punch over 200 mL glasses will allow: 6650/200=33 glasses, and a small remainder of 50 milliliters