Hey there! :) How are you? Basically what you said is right.
Question 1: There are 16 oz (ounces) in a pound, so we do 64/16= 4 lbs (pounds).
Question 2: If Jack has 3 pounds of pasta, that would mean he has 48 ounces, since 1 pound is 16 oz, so 16*3= 48 ounces.
Hoped I helped! Have a nice day, and keep smiling! :)