In a class of 50 students 30 study biology and 27 study chemistry .each students study at least one subject.1.illustrate the information on Venn diagram
Before you actually do that, it might be a good idea to do some
preliminary arithmetic.
let the number that study both be x
study only biology = 30-x
study only chemistry = 27-x
30-x + x + 27-x = 50
-x = -7
x = 7
then
study only biology = 23
study only chemistry = 20
study both = 7
now you can do your Venn diagram.