Okay. I'm guessing that you are asking how many guests she has coming, because she's serving 3/4 to each of them and her juice jar hold 12 pints of juice. What we would have to do is divide, because there is a fraction in the problem. In other words, Keep the first number (12) the same, change to division sign into a multiplication sign, and then flip the fraction around (change 3/4 to 4/3). The problem would be 12/1 * 4/3. Multiply straight across both fractions to get 48/3. 48/3=16. Jessica has 16 guests at her party.