A certain company has equally qualified applicants for 4 open positions. How many different groups of 4 applicants can be chosen by the company to fill the positions if the order of selection does not matter?
A. 18
B. 72
C. 180
D. 1,260
E. 3,060
Λύση (E):
Εφαρμόζουμε τον τύπο του Συνδυασμού (Combination) για να βρούμε το πλήθος των τετράδων που μπορούμε να επιλέξουμε από 18 συνολικά άτομα :
[18! / 14!4!]= (18*17*16*15)/(4*3*2) = 12*17*15 = 3,060
![Everyone believed the team was favored with athletic talent and a seasoned, successful coaching staff; […]](https://www.uniperfect.gr/wp-content/uploads/2021/02/verbal-1.jpg)
![Although the initial cost of installing solar panels to produce electricity can be _______, the financial benefits […]](https://www.uniperfect.gr/wp-content/uploads/2021/02/math-2.jpg)