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 percent of the people surveyed neither watch the news on $T.V.$ nor read a newspaper?

Let $U$ be the universal set and $A \cup B \cup C = U$. Then $\{ (A - B) \cup (B - C) \cup (C - A)\} '$ is equal to

The range of $f(x) = \cos x - \sin x$ is

In a city $20$ percent of the population travels by car,$50$ percent travels by bus and $10$ percent travels by both car and bus. Then the percentage of persons travelling by car or bus is......$\%$.

$A$ set contains $2n + 1$ elements. The number of subsets of this set containing more than $n$ elements is equal to

In a class of $140$ students numbered $1$ to $140$,all even-numbered students opted for the Mathematics course,those whose number is divisible by $3$ opted for the Physics course,and those whose number is divisible by $5$ opted for the Chemistry course. The number of students who did not opt for any of the three courses is: