A surverys is taken of 300 college students about whether they eat breakfast and whether they have a job. Two hundred seventy eat breakfast and 150 have a job.

Question

Twenty have a job and do not eat breakfast. 

A) draw a ven diagram that displays these results 

 

Answer 1

Draw one circle representing Breakfast and another circle, partially overlapping, representing Job.

 

Let a= no. of students outside all circles; let b = number in circle B but not within the overlapping 'leaf' shape area that is common to both circles.

 

Let c = no. of students in the common area (overlapping circles).

 

Let j = no. of students in circle J but not within the common area.

 

a+b+c+j = 300

b+c = 270

c+j = 150

j = 20 

 

These equations represent the system described by the VENN (two n's) diagram.

 

4 equations, 4 unknowns, you can solve!