Question

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?

Answer 1

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