Step-by-Step Solution

Topic: Matrix Multiplication & Applications

(I) COST MATRIX A

The cost per communication mode can be represented as a column matrix.

A =

15
10
25

(II) CONTACTS MATRIX B

The number of contacts for each village can be represented as a row in a matrix. Village X is the first row, and Village Y is the second row.

B =

100 150 110
150 200 150

(III) CALCULATING TOTAL COSTS

The total cost for each village is found by multiplying the contacts matrix B by the cost matrix A.

Total Cost = B × A

100 150 110
150 200 150

×

15
10
25

=

(100×15) + (150×10) + (110×25)
(150×15) + (200×10) + (150×25)
=

1500 + 1500 + 2750
2250 + 2000 + 3750

=

5750
8000

(III)(A) COST FOR VILLAGE X

The cost for Village X is the first element of the resulting matrix.

Cost for Village X = ₹ 5,750

(III)(B) COST FOR VILLAGE Y

The cost for Village Y is the second element of the resulting matrix.

Cost for Village Y = ₹ 8,000