In a parliament election, a political party hired a public relations firm to promote its candidates in three ways − telephone,

According to the question,

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

$A=\left[\begin{array}{r}140 \\ 200 \\ 150\end{array}\right] \begin{gathered}\text { Telephone } \\ \text { House calls } \\ \text { Letters }\end{gathered}$

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

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

$B A=\left[\begin{array}{ccc}1000 & 500 & 5000 \\ 3000 & 1000 & 10000\end{array}\right]\left[\begin{array}{l}140 \\ 200 \\ 150\end{array}\right]$

$=\left[\begin{array}{c}140000+100000+750000 \\ 420000+200000+1500000\end{array}\right]$

$=\left[\begin{array}{c}990000 \\ 2120000\end{array}\right]$

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.