how do you figure these out?:
1. P(8,2)
2. C(12,4) * C(8,3)
3. C(5,2)
4. C(12,7)

Question

how do you figure these out?:
1. P(8,2) 
2. C(12,4) * C(8,3)
3. C(5,2) 
4. C(12,7)

amistre64 · Answer

the are nPr  and   nCr

amistre64 · Answer

you simply need to do them on a calculator for the most part for ease

amistre64 · Answer

P(8,2) = 8*7 = 56

anonymous · Answer

yes! what she said! im doing this online school and they dont teach youanything!

amistre64 · Answer

C(5,2) i ssimple enough as well; 1,5,10,10,5,1;  id go with 5

amistre64 · Answer

C(n,r) is a shorter version of:

P(n,r)/r!  the "!" might be off cause i cant recall it clearly

amistre64 · Answer

C(5,3) should be 10

P(5,3)/3! = 5.4.3/3.2 = 5.2 = 10 ... id say the factorial notation is good

amistre64 · Answer

C(12,7) 

12.11.10.9.8.7.6
----------------
     7.6.5.4.3.2

6.11.2.3.2 = 66.12 = 12(60+6) = 720+72 = 792?  gonna have to dbl chk me steps

amistre64 · Answer

yay its right

amistre64 · Answer

C(12,4) * C(8,3)

12.11.10.9   8.7.6
----------  -----
      4.3.2       3.2


3.11.5.3.8.7

45.56.11

    495
      56
------
   2970
 2475
-------
 27720   ; gonna really have to check that ont :)

amistre64 · Answer

27720 .... its good

anonymous · Answer

your right!

anonymous · Answer

thank you so much! your my savior!

amistre64 · Answer

youre welcome :)