Find it by multiplying 40 by 1/5.
1/5 is the same thing as .2, by the way. You can use whichever one, whichever one is easiest for you.
1/5(40)=
1 * 40= 40
5 * 1= 5
40 divided by 5 is 8.
The answer is 8. One fifth of the class is 8 students.
Hope this helps!