by StaceyKoprince Thu Apr 26, 2007 3:03 am
I can't draw a Venn diagram here - but you can look at the diagram in the official explanation if you need to visualize.
20 = front porches
20 = front yards
40 = back yards
So, at the least, there are 40 houses. A house could have 1, 2, or all 3 of the above characteristics, or it could have none of them.
(You said you had trouble with statement 2, so I'll only address that one.)
Statement 2 says that, if a house has a front porch, then it does not have a front yard. So the first two categories, above, don't overlap. I can conclude that I have at least 40 houses (20 with front porches and 20 with front yards - and these could overlap completely with the 40 that have backyards to give 40 houses total) but I could also have, say 80 houses: 20 with only front porches, 20 more with only front yards, and 40 more with only back yards. Or some other combo - but I've just found two different amounts, so I can stop here because I can't answer the question with this statement.
Stacey Koprince
Instructor
Content & Curriculum Lead
ManhattanPrep