6. 3/4 of a box of laundry detergent is enough to wash 15 loads. How many loads could be washed with the whole box?
This problem could be restated as
15 is 3/4 of how many loads?
"Of" means multiply, so we are looking for what we have to multiply times 3/4 to get 15. To find what you are supposed to multiply, divide.
Invert and multiply.