Question 1198390
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In case A, 15 of the 200 patients are chosen; and they are 5 of the 40 cardiac patients and 10 of the 100 cancer patients.  The probability is<br><pre>
  (40 choose 5)*(100 choose 10)
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       200 choose 15</pre>
Use a calculator and express the result in the desired/required form.<br>
Case B is similar; the probability is<br><pre>
  (40 choose 2)*(100 choose 5)*(60 choose 4)
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             200 choose 11</pre>