A radio station has to choose two days of the seven in a week to broadcast a certain program, and that set will repeat each week. The program can be broadcast equally on any of the seven weekdays —- weekdays vs. weekends don’t matter at all —- nor does it matter whether the days the program airs are adjacent or not. Absolutely any two of the seven weekdays can be chosen. How many different two-day combinations of the seven weekdays can be constructed?  Choose one.
A) 9	B) 15	C) 21	D) 35	E) 56
Pick 2 days out of 7.. 7212 = 21   Answer : 21
<result>C</result>
A radio station has to choose two days of the seven in a week to broadcast a certain program, and that set will repeat each week. The program can be broadcast equally on any of the seven weekdays —- weekdays vs. weekends don’t matter at all —- nor does it matter whether the days the program airs are adjacent or not. Absolutely any two of the seven weekdays can be chosen. How many different two-day combinations of the seven weekdays can be constructed?