## GOODMAN 3 years ago How many 7 digit phone numbers can be formed if the first digit cannot be 0 or 1?

1. imranmeah91

well, let's write out each posibility for each digit and then multiply

2. GOODMAN

I was told to use the Counting Principle

3. imranmeah91

first one can't be 0 or 1 , so we got only 8 possibilities

4. RyanE

8*10*10*10*10*10*10

5. imranmeah91

the other digits have 10 possibilties so we multiplies them all

6. GOODMAN

Okay, so we delete 2 outta the 10 possibliity.

7. imranmeah91

like Ryan did above

8. lgbasallote

you're not planning on stalking someone are you @GOODMAN /:) he

9. GOODMAN

Wait, how do we know that the others have 10 possibilities, doesnt it apply to the others as well?

10. lgbasallote

jk goodie :DDD

11. imranmeah91

well, only first digit can't be 0 or 1 ; other digits can be any number from 0 to 9

12. GOODMAN

Ohhh, okay, got it!

13. GOODMAN

I need help with one more if you dont mind..

14. GOODMAN

A photographer is taking a picture o f a bride and groom together with 6 attendants. How many ways can he arrange the 8 people in a line if hte bride and groom stand in the middle?

15. imranmeah91

@satellite73

16. satellite73

yes?

17. imranmeah91

little help with photographer problem

18. satellite73

ok ____, ___, ____, B G ____, ____, _____

19. satellite73

$6!$

20. GOODMAN

Thats it?

21. imranmeah91

yep

22. GOODMAN

How?

23. satellite73

that looks right to me

24. agreene

what all of a sudden this has to be in base 10?

25. satellite73

this might surprise you and this might amaze you

26. satellite73

but i am going to knock out joe frazier !

27. GOODMAN

Huh?

28. satellite73

btw it is $6!=6\times 5\times 4\times 3\times 2=720$

29. GOODMAN

Yea, i knw what factorials are, but whats is Joe Frazier got to do with this, lol.

30. satellite73

Float like a butterfly, sting like a bee

31. satellite73

His hands can't hit what his eyes can't see.

32. lgbasallote

he beat muhammad ali....

33. GOODMAN

Hahaha, thats nice.