In a survey of a town, it was found that 65% of the people surveyed watch the news on T.V., 40% read a newspaper and 25% read a newspaper and watch the news on T.V. What per cent of the people surveyed neither watch the news on T.V. nor read a newspaper?

Let the total number of people in the town be $$100x$$

Now, 65% of the people surveyed watch the news on T.V., 40% read a newspaper and 25% read a newspaper and watch the news on T.V.

=> $$a+b = 65x$$

$$b+c = 40x$$

$$b = 25x$$

Solving above equations, we get :

=> $$a = 40x$$ and $$c = 15x$$

Also, $$a+b+c+d = 100x$$

=> $$40x + 25x + 15x + d = 100x$$

=> $$d = 20x$$

$$\therefore$$ 20% of the people neither watch news on TV nor read the newspaper.