1.

If n p r =840 and n c r =35 , then find r.

Answer»

><P>

N

C

R

n

P

r

=r!=

35

840

=24⇒r=4

n

P

r

=

(n−r)!

n!

=840

⇒n×(n−1)×(n−2)×(n−3)=840

⇒840=4×5×6×7

⇒n=7


Discussion

No Comment Found

Related InterviewSolutions