There are 15 research doctors participating in the study and the research board needs to be established with the offices of director, assistant director, quality control analyst, and correspondent. (doctors can only hold one office on the research board.) determine how many ways this research board can be chosen and explain your process.

32760

Step-by-step explanation:

There are 4 positions on the board.  There are 15 possible candidates for the first position.  That leaves 14 candidates for the second position.  Which leaves 13 for the third position, and 12 for the fourth position.

15 × 14 × 13 × 12 = 32760

50-38=12

step-by-step explanation:

x= cost per bracelet

number of bracelets * x + shipping charge = total cost

so

9x+9=72