Okay. To find the answer to this question, let's multiply both fractions together. 3 3/5 as an improper fraction is 18/5 and 1 3/10 as an improper fraction is 13/10. Multiply straight across to get the values. 18/5 * 13/10 is 234/50 or 4 17/25 in mixed number form. Michelle's Snack Shack went through 4 17/25 bottles of mustard.