English

In a Parliament Election, a Political Party Hired a Public Relations Firm to Promote Its Candidates in Three Ways − Telephone, House Calls and Letters. - Mathematics

Advertisements
Advertisements

Question

In a parliament election, a political party hired a public relations firm to promote its candidates in three ways − telephone, house calls and letters. The cost per contact (in paisa) is given in matrix A as
\[A = \begin{bmatrix}140 \\ 200 \\ 150\end{bmatrix}\begin{array} \text{Telephone}\\{\text{House calls }}\\ \text{Letters}\end{array}\]

The number of contacts of each type made in two cities X and Y is given in the matrix B as

\[\begin{array}"Telephone & House calls & Letters\end{array}\]

\[B = \begin{bmatrix}1000 & 500 & 5000 \\ 3000 & 1000 & 10000\end{bmatrix}\begin{array} \\City   X \\ City Y\end{array}\]

Find the total amount spent by the party in the two cities.

What should one consider before casting his/her vote − party's promotional activity of their social activities?

 
Sum

Solution

According to the question,

Let A be the matrix showing the cost per contact (in paisa).

\[A = \begin{bmatrix}140 \\ 200 \\ 150\end{bmatrix}\begin{array}\text{Telephone }\\{\text{House calls}} \\\text{ Letters}\end{array}\]

And, B be a matrix showing the number of contacts of each type made in two cities X and Y.

\[\begin{array}\text{Telephone }& {\text{House calls}} &\text{Letters}\end{array}\]

\[B = \begin{bmatrix}1000 & 500 & 5000 \\ 3000 & 1000 & 10000\end{bmatrix}\begin{array}\text{City X} \\ City Y\end{array}\]

Now, the total amount spent by the party in the two cities will be shown by BA.

\[BA = \begin{bmatrix}1000 & 500 & 5000 \\ 3000 & 1000 & 10000\end{bmatrix}\begin{bmatrix}140 \\ 200 \\ 150\end{bmatrix}\]

`=[[140000 + 100000 + 750000],[420000 + 200000 + 1500000]]`

` = [[990000 ],[2120000]]`

Hence, the total amount spent by the party in the two cities is
X: ₹9900
Y: ₹21200

One should consider social activities of a party before casting his/her vote.

shaalaa.com
  Is there an error in this question or solution?
Chapter 5: Algebra of Matrices - Exercise 5.3 [Page 47]

APPEARS IN

RD Sharma Mathematics [English] Class 12
Chapter 5 Algebra of Matrices
Exercise 5.3 | Q 77 | Page 47

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Compute the indicated product:

`[(a,b),(-b,a)][(a,-b),(b,a)]`


Compute the indicated product:

`[(2,3,4),(3,4,5),(4,5,6)][(1,-3,5),(0,2,4), (3,0,5)]`


Compute the products AB and BA whichever exists in each of the following cases:

 [ab]`[[c],[d]]`+ [a, b, c, d] `[[a],[b],[c],[d]]`


Evaluate the following:

`([[1              3],[-1    -4]]+[[3        -2],[-1         1]])[[1         3           5],[2            4               6]]`


Evaluate the following:

`[[],[1  2  3],[]]` `[[1     0      2],[2       0         1],[0          1       2]]` `[[2],[4],[6]]`


If A =  `[[4       2],[-1        1]]` 

, prove that (A − 2I) (A − 3I) = O

 

If A =  `[[1    1],[0    1]]`  show that A2 = `[[1       2],[0          1]]` and A3 = `[[1        3],[0       1]]`


For the following matrices verify the associativity of matrix multiplication i.e. (ABC = A(BC):

`A=[[4       2        3],[1       1          2],[3         0          1]]`=`B=[[1        -1          1],[0         1            2],[2           -1          1]]` and  `C= [[1       2       -1],[3       0         1],[0         0         1]]` 


If


\[A = \begin{bmatrix}3 & 1 \\ - 1 & 2\end{bmatrix}\]show that A2 − 5A + 7I = O use this to find A4.


If f (x) = x3 + 4x2 − x, find f (A), where\[A = \begin{bmatrix}0 & 1 & 2 \\ 2 & - 3 & 0 \\ 1 & - 1 & 0\end{bmatrix}\]


`A=[[1,2,2],[2,1,2],[2,2,1]]`, then prove that A2 − 4A − 5I = 0


Find the matrix A such that    [2  1  3 ] `[[-1,0,-1],[-1,1,0],[0,1,1]] [[1],[0],[-1]]=A`


 If `P(x)=[[cos x,sin x],[-sin x,cos x]],` then show that `P(x),P(y)=P(x+y)=P(y)P(x).`


Let A and B be square matrices of the same order. Does (A + B)2 = A2 + 2AB + B2 hold? If not, why?

 

If A and B are square matrices of the same order, explain, why in general

(A + B)2 ≠ A2 + 2AB + B2


If A and B are square matrices of the same order, explain, why in general

(− B)2 ≠ A2 − 2AB + B2


If A and B are square matrices of the same order, explain, why in general

 (A + B) (A − B) ≠ A2 − B2


The cooperative stores of a particular school has 10 dozen physics books, 8 dozen chemistry books and 5 dozen mathematics books. Their selling prices are Rs. 8.30, Rs. 3.45 and Rs. 4.50 each respectively. Find the total amount the store will receive from selling all the items.

 

There are 2 families A and B. There are 4 men, 6 women and 2 children in family A, and 2 men, 2 women and 4 children in family B. The recommend daily amount of calories is 2400 for men, 1900 for women, 1800 for children and 45 grams of proteins for men, 55 grams for women and 33 grams for children. Represent the above information using matrix. Using matrix multiplication, calculate the total requirement of calories and proteins for each of the two families. What awareness can you create among people about the planned diet from this question?


The monthly incomes of Aryan and Babban are in the ratio 3 : 4 and their monthly expenditures are in the ratio 5 : 7. If each saves ₹ 15,000 per month, find their monthly incomes using matrix method. This problem reflects which value?


Let  `A =[[2,-3],[-7,5]]` And `B=[[1,0],[2,-4]]` verify that 

(AB)T = BT AT

 

If `A= [[3],[5],[2]]` And B=[1  0   4] , Verify that `(AB)^T=B^TA^T` 


 If \[A = \begin{bmatrix}\sin \alpha & \cos \alpha \\ - \cos \alpha & \sin \alpha\end{bmatrix}\] , verify that AT A = I2.
 

 If \[A = \begin{bmatrix}4 & 3 \\ 1 & 2\end{bmatrix} and B = \binom{ - 4}{ 3}\] 

write AB.

 

If  \[\begin{bmatrix}1 & 2 \\ 3 & 4\end{bmatrix}\begin{bmatrix}3 & 1 \\ 2 & 5\end{bmatrix} = \begin{bmatrix}7 & 11 \\ k & 23\end{bmatrix}\] ,then write the value of k.


What is the total number of 2 × 2 matrices with each entry 0 or 1?


If \[A = \begin{bmatrix}1 & 0 & 0 \\ 0 & 1 & 0 \\ a & b & - 1\end{bmatrix}\] , then A2 is equal to ___________ .


If A and B are two matrices such that AB = A and BA = B, then B2 is equal to


Let A = \[\begin{bmatrix}a & 0 & 0 \\ 0 & a & 0 \\ 0 & 0 & a\end{bmatrix}\], then An is equal to

 


If A = [aij] is a scalar matrix of order n × n such that aii = k, for all i, then trace of A is equal to


If A and B are square matrices of the same order, then (A + B)(A − B) is equal to 


Let A and B be square matrices of the order 3 × 3. Is (AB)2 = A2B2? Give reasons.


Let A = `[(1, 2),(-1, 3)]`, B = `[(4, 0),(1, 5)]`, C = `[(2, 0),(1, -2)]` and a = 4, b = –2. Show that: A(BC) = (AB)C


If A = `[(1, 1, 1),(0, 1, 1),(0, 0, 1)]` and M = A + A2 + A3 + .... + A20, then the sum of all the elements of the matrix M is equal to ______.


If A = `[(a, b),(b, a)]` and A2 = `[(α, β),(β, α)]`, then ______.


If A = `[(-3, -2, -4),(2, 1, 2),(2, 1, 3)]`, B = `[(1, 2, 0),(-2, -1, -2),(0, -1, 1)]` then find AB and use it to solve the following system of equations:

x – 2y = 3

2x – y – z = 2

–2y + z = 3


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×