Running on a treadmill for 30 minutes...?!

Running is a great way to lose weight :)
Eating around 1200 would be good, its a healthy calorie intake. Make sure to include a lot of healthy food, fruits, veggies, lean protein, nuts, etc
Yes, it'd be possible for you to lose 20 or more by june if you keep this up! :) Good luck!

Losing weight as a whole will trim you down everywhere. There is no such thing as spot reduction. But 30 min of running might burn you 300 calories max so you need to focus on your diet. Without a proper diet, the 30 min of cardio will go to waste.

diet and exercise are the key but 20 lbs in 2 months is a lot.

quick result diets like atkins often don't offer results that last