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Showing posts with label Statistics. Show all posts
Showing posts with label Statistics. Show all posts

Tuesday, August 27, 2013

Permutation Problems, 3

Category: Algebra, Statistics

"Published in Newark, California, USA"

A passenger train consists of 3 baggage cars, 5 day coaches, and 2 parlor cars. In how many ways can the train be arranged if the 3 baggage cars must come up front?

Solution:

The given word problem is about permutation problem because it involves the number of ways in arranging the objects or things. 

This permutation type is different and it is called a Distinguishable Permutation. 

If a set of n objects consists of k different kinds of objects with n1, objects of the first kind, n2 objects of the second kind, n3 objects of the third kind, and so on, where n1 + n2 + ......... + nk = n, then the number of distinguishable permutations of these objects is 


Now, in the given problem, if

n = 10 train cars in total
n1 = 3 baggage cars
n2 = 5 day coaches
n3 = 2 parlor cars

then, the number of ways in arranging the 10 train cars will be equal to






If the 3 baggage cars must come up front, then the number of ways will be equal to


You have to multiply the previous ways by 3! because the three baggage cars themselves can be arranged in different ways at the front. Therefore, the final answer is




 

Tuesday, May 21, 2013

Permutation Problems, 2

Category: Algebra, Statistics

"Published in Suisun City, California, USA"

A man bought three vanilla ice cream cones, two chocolate cones, four strawberry cones, and five butterscotch cones for his 14 children. In how many ways can he distribute  the cones among his children?

Solution:

The given word problem above is about permutations but it is a different type which is called a Distinguishable Permutation.  

If a set of n objects consists of k different kinds of objects with n1, objects of the first kind, n2 objects of the second kind, n3 objects of the third kind, and so on, where n1 + n2 + ......... + nk = n, then the number of distinguishable permutations of these objects is 


Now, let's go back to the given problem, if n = 14 children, n1 = 3 vanilla ice cream cones, n2 = 2 chocolate cones, n3 = 4 strawberry cones, and n4 = 5 butterscotch cones, then the number of ways to distribute the cones among to his children is


  



Monday, May 20, 2013

Permutation Problems

Category: Algebra, Statistics

"Published in Newark, California, USA"

If polygons are labeled by placing letters at their vertices, how many ways are there of labeling (a) a triangle, (b) a quadrilateral, (c) a hexagon with the first 10 letters of the alphabet?

Solution:

The given word problem above is about permutations. Permutation is an arrangement of a number of objects in a definite order. To "permute" a set of objects means to arrange them in a definite order. The number of permutations of n things taken r at a time is given by the formula


where n! (read as n factorial) is equal to n(n -1)(n - 2)......3∙2∙1. Take note that the values of n and r must be zero and positive numbers only. 0! is equal to 1. 

Now, let's go back to the given problem and solve for the permutations of the given polynomials. 

(a) For a triangle, the number of ways to label the vertices with the first 10  letters of the alphabet are










(b) For a quadrilateral, the number of ways to label the vertices with the first 10  letters of the alphabet are





 (c) For a hexagon, the number of ways to label the vertices with the first 10  letters of the alphabet are