I hope you are
familiar with Venn diagram....this is a very useful tool in solving this type
of problems..i just cant draw 3 intersecting circles here to illustrate
the diagram..but as u find how to use it..start filling up the center of the
intersecting 3 circles with the element common to them (that is 4 in this
case)...then expand outwardly from the center..and proceed to the elements
where only 2 categories share( 6, 10 and 9 in this case).
And
you can get all the information needed easily..
Students who took none
of the 3 subjects = 20
Students who took PE but not BIO and ENGLISH = 16
Students who took BIO and
PE but not English = 2
