A scientist used a unique two-color code to identify each of the test subjects involved in a certain study. If the scientist found that choosing from among five colors produced enough color codes to identify all but 6 of the test subjects, how many test subjects were in the study? (Assume that the order of the colors in the codes does not matter.)
Choose the correct choice.
A) 14
B) 15
C) 16
D) 17
E) 18
5162 = 10   The number of test subjects is  10 + 6= 
<gadget id="calculator"> 10 + 6</gadget>
<output>16</output>
16   The answer is 16.
<result>C</result>
A scientist used a unique two-color code to identify each of the test subjects involved in a certain study. If the scientist found that choosing from among five colors produced enough color codes to identify all but 6 of the test subjects, how many test subjects were in the study? (Assume that the order of the colors in the codes does not matter.)