So basically you could say that there were 4/3 antibiotic prescriptions, therefore there would be 3/3 tranquilizers. And since if you add the two together, getting 7/3, you can just divide 84 by 7 and 7/3 by 7, which would result in 12 and 1/3. Since 1/3 is 1/3 of 3/3, multiply 12 by 3 and you would get 36 tranquilizers. That probably made no sense.
At the end of the day, a pharmacist counted and found she has 4/3 as many prescriptions for antibiotics as she did tranquilizers. She had 84 prescriptions for the two types of drugs. How many prescriptions did she have for tranquilizers?