Answer:
They sold a total of 120 milkshakes that day.
Step-by-step explanation:
We can set up a proportion
48 vanilla milkshakes=40% of X , x is the unknown of total number of milkshakes.
48=40%X
X=48/0.4
X= 128 total number of milkshakes
Note: If you have some value, , and it is of the total amount, you can find the value by doing the equation v/x x 100