In a battle,$70\%$ of the soldiers lost one eye,$80\%$ lost one ear,$75\%$ lost one arm,and $85\%$ lost one leg. If $x\%$ of the soldiers lost all four,what is the minimum value of $x$?

Of the members of three athletic teams in a school,$21$ are in the cricket team,$26$ are in the hockey team,and $29$ are in the football team. Among them,$14$ play hockey and cricket,$15$ play hockey and football,and $12$ play football and cricket. Eight play all the three games. The total number of members in the three athletic teams is:

In a class of $60$ students,$25$ students play cricket and $20$ students play tennis,and $10$ students play both the games. The number of students who play neither is:

$A$ number is chosen from the first $100$ natural numbers. The probability that the number is even or divisible by $5$ is:

Sets $A$ and $B$ have $3$ and $6$ elements respectively. What can be the minimum number of elements in $A \cup B$?

If $P(A) = \frac{2}{5}$,$P(B) = \frac{1}{4}$ and $P(A \cup B) = \frac{1}{2}$,then $P(A' \cup B') = $