[AdminKeymaster]

Im doing Permutations in math class. If you dont know what those are, then just leave this topic. There's nothing you can do to help…Here's the problem:::[hr]How many seven-digit phone numbers are available if a digit can only be used once and the first number cannot be 0 or 1?[hr]I looked in the back of the book and it says the answer is 483,840.I know I can just put that but I need to show my work.....So if you figure this out please post how you did it. Thanks.

[Silent NagaMember]

Screw showing your work, just write the answer. XDDude, I think you totally have the same math problem as me one time. You using the McDougal-Littell Pre-Algebra?

[AdminKeymaster]

Screw showing your work, just write the answer. XDDude, I think you totally have the same math problem as me one time. You using the McDougal-Littell Pre-Algebra?

I'm not taking Pre-Algebra until 8th grade. Im in 7th right now. (But I am using a standard 8th grade Textbook because Im enriched)So nope. lol

[YoshipatrolMember]

The answer my good man would be8 x 9 x 8 x 7 x 6 x 5 x 4

[AdminKeymaster]

The answer my good man would be8 x 9 x 8 x 7 x 6 x 5 x 4

I see why you would do P(8,5)...but why 8 x 9?(I think you just did an equation to get that #)Thats not really what im looking for....

[YoshipatrolMember]

The answer my good man would be8 x 9 x 8 x 7 x 6 x 5 x 4

I see why you would do P(8,5)...but why 8 x 9?(I think you just did an equation to get that #)Thats not really what im looking for....

Explaining fractorials is a pain... What ARE you looking for?

[AdminKeymaster]

The answer my good man would be8 x 9 x 8 x 7 x 6 x 5 x 4

I see why you would do P(8,5)...but why 8 x 9?(I think you just did an equation to get that #)Thats not really what im looking for....

Explaining fractorials is a pain... What ARE you looking for?

The way to get the answer. you said just a multiplication problem to get the #.You dont need to really need to explain factorials to me, just say why you did this and that. (If thats too much just say it, and ill go ask my dad for help)

[YoshipatrolMember]

Because each digit can only be used. The first digit can not be 0 or 1 so thats the 8 I got there. The second number can be 0 or 1 but not the first number repeated that leaves 9 numbers. Then the third number can't be repeated either so we're back to 8 and we keep going. If that makes sense.

[AdminKeymaster]

OK, I see where you went with it now. Thanks Yoshi!

[YoshipatrolMember]

OK, I see where you went with it now. Thanks Yoshi!

No problem! Tee hee!

[JoeWvernMember]

MAN! so late. Come on I have a 101 average in advanced math and in math team. I'm liek the geekiest person ever. Lol, anyways i'm only learning pre algerbra anyways.

[YoshipatrolMember]

MAN! so late. Come on I have a 101 average in advanced math and in math team. I'm liek the geekiest person ever. Lol, anyways i'm only learning pre algerbra anyways.

^ Pfft nerd rant! LOL JK Joe I love ya!

[Author]

Posts