Seven out of every 8 students surveyed owns a bike. the difference between the number of students who own a bike and those who do not is 72. how many students were surveyed?

So if x people were surveyed, people owned a bike and   did not.

The difference between them is 72:
x-\frac{1}{8} [/tex] =72
so this means that
x=72

let's simplify:

x=72

and divide by 3:

x=24

and mupliply by 4:

x=96

so 96 people were surveyed