Please help

Asked by Rahulsinha1993 | 5th Nov, 2009, 10:54: AM

Expert Answer:

nCr  = nPr/ r !  

r ! = nPr/nCr  = 2520/21 = 120.

Since 5 ! = 120.

r = 5.

Regards,

Team,

TopperLearning.

 

Answered by  | 5th Nov, 2009, 03:15: PM

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