There are 42 distinct numbers in set M, there are 28 distinct numbers in set N, and there are 12 distinct numbers that are in both sets M and N. Set H is the set containing the elements that are in at least one of sets M and N. How many elements are in set H? Choices.
A) 39 B) 40 C) 51 D) 58 E) 63
{Total} = {M} + {N} - {Both}   {Total} = 42 + 28 - 12= 
<gadget id="calculator">42 + 28 - 12</gadget>
<output>58</output>
58.   Answer: 58.
<result>D</result>
There are 42 distinct numbers in set M, there are 28 distinct numbers in set N, and there are 12 distinct numbers that are in both sets M and N. Set H is the set containing the elements that are in at least one of sets M and N. How many elements are in set H?