sets query

kouffaley

hI GUYS CAN ANYONE HELP PLEASE:
A group of 100 students were asked which of the three modules Multimedia, Networking and Software Development they studied. It was found that 16 didn’t study any of the three. 68 studied Multimedia, 28 studied networking and 35 studied software development. Of these students, 3 studied both multimedia and networking but not software development, 5 studied software development and networking but not multimedia and 5 studied multimedia and software development but not networking.

How many students studied only one subject?

MathsManiac

The best way is probably to draw a Venn Diagram. (There's a typo in that diagram: the right hand loop should have "unique to B"; but it's the best I could find in a hurry!)

Draw the three intersecting circles, and then try to insert the information as to how many elements (people) are in each part of the diagram, working "from the inside out", (that is, satring in the middle, then moving to the areas common to two sets, then the remaining areas). In this case, you don't know how many people studied all three, so you could let that be represented by x. You can fill out the other areas of the diagram, in terms of x as necessary. Then, you should be able to use the fact that all areas of the diagram together, (incuding the 16 people outside all three loops) has to add upt to 100.

kouffaley

tHANKS THAT HELPD REALLY