Question 589915

There are 325 students in a college who have taken a course in calculus,
<pre>
N(C) = 325
</pre>
218 who have take a course in discrete mathematics,
<pre>
N(D) = 218
</pre>
and 144 who have taken a course in both calculus and discrete mathematics. 
<pre>
N(C and D) = 144
</pre>
How many students at this college have taken a course in either calculus or discrete mathematics? 
<pre>
N(C or D) = ?

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The formula is:

N(C or D) = N(C) + N(D) - N(C and D)

N(C or D) =  325 +  218 - 144

N(C or D) =  399   

Edwin</pre>