Yesterday's condiment consumption at Oliver's Snack Shack

Calculating Mustard Consumption

First, let's convert the mixed number of ketchup bottles to an improper fraction. 1 3/4 is equal to 7/4 when represented as a fraction.

Next, we multiply the amount of ketchup consumed by the ratio of mustard to ketchup. The ratio 1 9/10 is equivalent to 19/10 as an improper fraction.

Now, we multiply the amount of ketchup by the mustard ratio:

1 3/4 bottles of ketchup x 19/10 = (7/4) x (19/10) = 133/40 bottles of mustard

Therefore, Oliver's Snack Shack went through 133/40 bottles of mustard yesterday.