B. 1/40…. You divide 1/2 by 20 to find out how much hand sanitizer was used on each desk. You can keep change flip meaning keep the 1/2 change the division to multiplication and flip the 20 to 1/20 then multiply. 1/2 by 1/20 which equals 1/40.
He did not perform enough trials. The more trials you perform, the closer it gets to the predicted outcome.
Step-by-step explanation:
her this is the answer for the question