A survey of students at a university shows that 4 out of 5 drink coffee. Of the students who drink coffee, 1 out of 6 adds cream to it. If the university has 18,000 students, find the number of students who drink coffee with cream. How many students drink coffee with cream?

The number who drink coffee is 3/4 of 8000, so ...
... (3/4)×8000 = 6000.
Of those, 1/5 add cream, so the number of coffee drinkers who add cream to their coffee is ...
... (1/5)×6000 = 1200.

Alternate solutions
We have computed ...
... (1/5)×((3/4)×8000) = 1200
Since multiplication is associative, you can multiply the fractions first, if you wish:
... ((1/5)×(3/4))×8000 = (3/20)×8000
... = 24000/20 = 1200
or
... = 3×(8000/20) = 3×400 = 1200