Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
One example: Earth rotates on its axis once times in one day.
Solution is here: How many times does Earth rotate on its axis in one day?
Explanation: The given output correctly poses a question based on the scientific fact given.

Now, solve this: Design an experiment that tests multiple types of popcorn using repeated trials method should be used to determine the type of popcorn that produces the greatest number of popped kernels.
Solution:
Which method should be used to determine the type of popcorn that produces the greatest number of popped kernels?