Q75 of 307 Page 5

75. To promote making of toilets for women, an organization tried to generate awareness through (i) house calls (ii) letters, and (iii) announcements. The cost for each mode per attempt is given below :

(i) ₹ 50


(ii) ₹ 20


(iii) ₹ 40


The number of attempts made in three villages X, Y and Z are given below :



Find the total cost incurred by the organization for three villages separately, using matrices.

Given costs in Rs for making different types of attempts.


Cost for one house call = Rs 50


Cost for one letter = Rs 20


Cost for one announcement = Rs 40


Hence, the costs per contact in Rs for different types of contacting the people can be expressed in matrix form as -



Let matrix B contain the number of attempts of each type made in the three villages X, Y and Z.


From the given information, the number of attempts made can be expressed in the matrix form as -



Now, the total cost incurred by the organization in the three villages for creating awareness can be obtained by taking the product of the matrices B and A.






Cost incurred in village X = Rs 30000


Cost incurred in village Y = Rs 23000


Cost incurred in village Z = Rs 39000


Thus, the cost incurred by the organization in villages X, Y and Z is Rs 30000, Rs 23000 and Rs 39000 respectively.


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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


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



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 or their social activities?