<PRE><B>Question 277508</B>
From a group of 100 students, 30 are taking math, 20 are taking chemistry, and of those totals 10 are taking both math and chemistry.What is the probability that a randomly selected student is taking math or chemistry?

my guess is the set of Math plus the set of Chemistry equals 50 students, the 2 sets intersect with 10 in each group, leaving 10 in the not interected portion of Chemistry and 20 in the not intersected portion of Math, that is a total of 30 in the not intersected portions of each group

(I drew 2 circles that intersected, one for Math and one for Chemistry.)

if I am right then 30/100 or 30% are taking Math or Chemistry and not both.

please let me know if I am wrong or if you have a better way of figuring this out
</PRE>