this is quite a classic problem i think but I am having difficulty finishing it off. If we have two stamps of positive values a and b, (greater than 1), what values can be expressed as a linear combination of these 2 stamps. If the stamps have a highest common factor greater than 1, then there...
How many 4 element subsets can you get from a 21 element set. I know the combination formula C(21,4)=5985. I was trying to see how this is working out though. I know there are 2^21 subsets of a 21 element set, I want to know how I can find the number of all the 4 element subsets without using...
How many combinations of three letters from the letters A,A,B,B,C,C,D are ther?
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I assumed 2 cases:
1. 2 letters are the same.
2. all the 3 are different.
And found 9 forms for the first case, and 24 for the second one. As you know my answer (33) is 20 more...
4 children out of 8 will be selected. But two oldest children can not be both chosen. Total number of combinations = ?
The mutually exclusive situations are really confusing me.
I know if they were independent, total n. of combinations would be
\frac{8!}{(8-4)!4!}=70
I need to subtract...
How do u calculate the the total number of combinations, given that you have n number of object and you will choose r of the objects, but x of these objects are mutually exclusive. Let x=2 for your explanations.
I kinda have an idea on how to do this, but i can't frecall an formula for the...
{1, x, x(x-1), x(x-1)(x-2)} you want to find the linear combinations that will give you 1, x, x^2, x^3
a + a(x) + a(x(x-1)) + a(x(x-1)(x-2)) = 1
a + a(x) + a(x(x-1)) + a(x(x-1)(x-2)) = x
a + a(x) + a(x(x-1)) + a(x(x-1)(x-2)) = x^2
a + a(x) + a(x(x-1)) + a(x(x-1)(x-2)) = x^3
I don't...
I'm currently taking Physics in High School and having problems with Vectors.
I apologize in advance if this is the wrong forum to post this on but here it is...
I have to Diagram the vector combinations on graph paper and find the resultant and the equilibant.
3 N at 120(degrees)...
Perhaps this isn't the right Forum for such topic, but it does fall under some philosophy.
Your brain thinks not all at once but in a progressive nature where you cannot possibly consider all thoughts at once of a subject or any multiple subjects. I believe it is a combination progression...
All n-variable combinations can exist within a word;
n=1 | a
n=2 | ab
n=3 | cabca
Is the fourth shortest word cabdcabcdabcadbca, and how long is the n:th word?
i was wondering how to calculate the posibilities that a security code could be. For instance if a jet ski security code consists of 4 numbers. each digit can be any number 1 through 5.
how many combinations can that make?
p.s. - I am not trying to steal a jet ski; I am just wondering.
I got this two problems, I can't figure them out...
A bookshelf contains m different books and n copies of each. How many different selections can be made from them?
and
In how many different ways can four letters be posted in four envelopes so that no one receives the correct letter?
How many ways can you select four letters out of the word parallelogram ?
The answer on the book is 150. For me I am stuck at using 8C4 and it seems to be the logical way. The reason I chose 8 is because some letters are repeating. So how can they have 150?
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THANK YOU.
Let us check these lists.
P(2) = {{},{0},{1},{0,1}} = 2^2 = 4
and also can be represented as:
00
01
10
11
P(3) = {{},{0},{1},{2},{0,1},{0,2},{1,2},{0,1,2}} = 2^3 = 8
and also can be represented...
I once read a very good explanation for the n! factor in the combinations formula but I can't find it. Can someone state the reason for it clearly please.
( N) = N!/n!/(N-n)!
( n)
The N!/(N-n)! comes about because there are that many ways to choose n things from N. N for the first...