Question #357c1

2 Answers
Apr 3, 2017

""_32 C_8 = 10,518,300 combinations

Explanation:

The form of a combination is ""_nC_r, where n = the total number and r = the subset.

""_32 C_8 = (n!)/(r!(n-r)!) = (32!)/(8! (32-8)!) = (32!)/(8!*24!)

=(32*31*30*29*28*27*26*25*24!)/(8*7*6*5*4*3*2*1*24!)

The 24! cancels:

=(32*31*30*29*28*27*26*25)/(8*7*6*5*4*3*2*1)

Factor: =(8*4*31*5*6*29*7*2*2*3*9*26*25)/(8*7*6*5*4*3*2)

Cancel numbers common in the numerator & denominator:
=31*29*2*9*26*25

= 10,518,300 combinations

If you have a TI-83, 84 calculator, you can type
32 MATH -> PRB " "3 " "8 ENTER

Apr 3, 2017

The result is 10 518 300 ways.

Explanation:

To calculate the number of ways that groups of eight can be chosen from a larger group of 32, we use the formula

""_nC_r = (n!)/((r!)(n-r)!)

So, in this case

""_32C_8 = (32!)/(8!*24!) = (32xx31xx30xx29xx28xx27xx26xx25)/(8xx7xx6xx5xx4xx3xx2xx1)

= 10 518 300

By the way, I believe the accepted notation is ""_nC_r