Let's start with the column and row totals, which should make things easier
Total <$20K = 69+112+102+13 = 296
total $20-30K 500
total >30K 404
TOTAL 296+500+404=1200
Rows,
<HS 69+36+2 = 107
HS 224
Some C 438
C 431
Check total: 107+224+438+431 = 1200, good
A. P(<HS) = 107/1200
because there are 107 folks who didn't finish high school out of the 1200 total.
B. P(<$20K) = 296/1200 = 37/150
C. P(>$30K & <HS)
Only 2 of 1200 folks fit this description, upper right box.
P(>$30K & <HS) = 2/1200 = 1/600
D. P(<$20K & C) = 13/1200
That's the bottom left box.
E. P(>$30K & HS) = 14/1200 = 7/600
F. P(<HS OR >$30K)
OR is usually more complicated. We have 107 who didn't finish high school and 404 more than $30K. We counted the 2 in the box <HS AND >$30K twice, so our total is 107 + 404 - 2 = 509
P(<HS OR >$30K) = 509/1200
