I excercise 5 days a week for 30 minutes.....will I loose weight doing just this?
You will gain, maintain or lose weight based on your caloric intake. Simple as that.
A person can do cardio for hours, lift weights diligently and do 300 sit-up's each day....but if they eat in excess of their needs, they'll gain weight/fat.
Fact is, there are millions of people who have lost weight by just diet alone. Adding exercise to the curriculum is not essential, but STRONGLY advised....for the calories it burns and other health benefits (respiratory, circulatory, psychological....just about everything!).
For most people here on this forum, your routine is on the weak side....limestix is correct; cardio should be at a moderate intensity and sustained for at least 30 minutes....and eventually work your way up to the level...say, of FlyinFree.
If you're in your 70's then your routine may be fine....but if you're younger and in good shape, I'd suggest amping it up a bit. Why don't you tell us more about yourself (age, weight, physical condition, etc).