I need help with my math homework, someone please help!!!

[dimava]

Eight Sprinters are running in a race. If there are no ties, in how many ways can:

a. First Place be awarded?

b. first and second places be awarded

c. first, second, and third places be awarded

d. all eight places be awarded

this isn't a trick question, i just dont know how to solve it, can someone please give me the answer to a, b, c, and d, and also explain what you did to get your answer

[kedaman]

1 = 8
8

2 = 28
8

3 = 56
8

8 = 8
8

[dimava]

i think that 2 = 64 or 2 = 2! or something, i'm not sure, but i'm pretty sure that 2, 3, 4 are wrong, if not, explain your logic, and how you got the answer

[Iain17]

Been a long time since i have lied with numbers (statistics), but i think it is something like.

a) 8

b) 8 ways of 1st place, * 7 ways for 2nd place

c) 8 ways of 1st place, * 7 ways for 2nd place * 6 ways for 3rd place

d) 8 ways of 1st place, * 7 ways for 2nd place * 6 ways for 3rd place * 5 ways for 4th place * 4 ways for 5th place * 3 ways for 6th place * 2 ways for 7th place * 1 ways for 8th place

[dimava]

ok, thanks..... here's one more:

A small business has its own internal phone system, Each phone number is four digits long, The first digit must be 2 to indicate an internal call, and the second digit cannot be 0. How many internal phone numberss are possible for this company?

now how would i go about solving this problem?

[kedaman]

actually i was looking at pascals triangle when finding out those. WEll they are binominal coeficients

900 numbers i guess that's 10^3-10^2

[kedaman]

BTW if you want the binominal formula:

n! / (k! * (n - k)!)

where n is total items to choose from and k amount of items to choose

[HarryW]

Do you ever do your own homework Dimava?

[dimava]

lol..... its just that sometimes i get stuck on it, and i have one more last problem:

The big breakfast at Dot's Restaurant offers diners one choice from each of the following:

eggs (fried, poached, scrambled, over-easy)
potatoes or grits
toast (wheat, white, or muffin)
meat (sausage, ham, or bacon)
juice (orange, grapefruit, tamato, apricot, grape, apple)

How many diffrent big breakfasts are there?

please tell me how to solve it

[HarryW]

If you were paying attention to the way the other guys on this thread solved your first 2 problems, you ought to be able to apply some of the same ideas to this problem. I know you're, like, 12 or something, but this isn't so hard. Don't you think you ought to do at least 1 out of 3 questions yourself?

[dimava]

ok, i see what you're saying, i'll try, and, jsut to get it correct, i'm asking for help on 3 out of 38 questions, and i'm 13 (since 11/1/00)

[Bjwbell]

I think there are around 400 different breakfeast, i don't know fore sure how close that is.
The way i did wast to break the different types of foods (ie Toast , eggs) into there own number so there fou different types of eggs so i did this
eggs1,eggs2,eggs3,eggs4 I did this four all the other types so
i could evaluate the numbers instead of the breakfeastes
I tried my method ou evaluateing the numbers with very simple numbers first(ie a1,a2,b1,b2).
I tried all the combination of a1,a2,b1,b2 to see if there was some rule that goverend how many combinations there where. I found out that how many different a's there are times the number of b's gives you the number of combinations(ie 2 a's, 2 b's combinations=2*2)

I'm not at all sure that that's correct so do it yourself to see if it is.


[Edited by Bjwbell on 11-05-2000 at 11:07 PM]

[HarryW]

Yes that's the correct method, assuming that there is no option not to have any or all of the ingredients.

Dimava, I take it back on the point about 1 question out of three if you have 38 questions.

[kedaman]

well dimiva you would have to start learning see what type of qwestion it is.

It's all about choices you find out how many there are, use + operator for or and * operator for and, so you do for the types of eggs and potatoes or grits is
(1+1+1+1) * (1+1)
and so on, you get 4*2*3*3*6 which should be 432

hope you get start thinking yourself soon, then you will notice how easy it really is

[dimava]

ok, thanks to all that helped