setting up a proportion

Question

A survey of college students shows that 4 our of 5 drink coffee. Of the students who drink coffee, 1 out of 8 adds cream. How many of the 56100 students add cream to their coffee?

Answer 1

4/5 drink coffee. 1/8 of those add cream. That creates the equation:

4/5 * 1/8, or:

4/(5*8)

 

A 4 is in common in both the numerator and denominator, so we can simplify:

1/(5*2), or 1/10 of the students use cream in coffee

 

56100 ÷ 10 = 5610 students.