As a nurse, part of your daily duties is to mix medications in the proper proportions for your patients. For one of your regular patients, you always mix Medication A with Medication B in the same proportion. Last week, your patient's doctor indicated that you should mix 90 milligrams of Medication A with 45 milligrams of Medication B. However this week, the doctor said to only use 30 milligrams of Medication B. How many milligrams of Medication A should be mixed this week?