And of course...you cannot spot reduce. You have to lose bodyfat from the entire body. The body chooses where to shed the fat.
I'm guessing you are female, as women tend to store fat in the butt and thighs, while men store it a little higher, in the abdomen.
If you slow down your cardio pace, you'll need more than 20 minutes.
Lift weights on different days or BEFORE cardio.
And lift heavy with lower reps. Light weight and high reps trains endurance.
Lastly Wilhelm is 100% correct...that losing fat requires a calorie deficit. You need to tell us what you eat, adn what your calorie intake is like on a daily basis.
you might wanna use the free version of FitDay.com to track your food journal. keep in mind that it's food list is not absolute. It can have discrepancies, but luckily the body works on trends, not individual calories, so an extra 50 or 100 cals one day is likely corrected by an unseen deficit later in the week.