Let $X = \{ $ Ram ,Geeta, Akbar $\} $ be the set of students of Class $\mathrm{XI}$, who are in school hockey team. Let $Y = \{ {\rm{ }}$ Geeta, David, Ashok $\} $ be the set of students from Class $\mathrm{XI}$ who are in the school football team. Find $X \cup Y$ and interpret the set.

Let $\mathrm{U}$ be the set of all triangles in a plane. If $\mathrm{A}$ is the set of all triangles with at least one angle different from $60^{\circ},$ what is $\mathrm{A} ^{\prime} ?$

In a class of $30$ pupils, $12$ take needle work, $16$ take physics and $18$ take history. If all the $30$ students take at least one subject and no one takes all three then the number of pupils taking $2$ subjects is

A market research group conducted a survey of $1000$ consumers and reported that $720$ consumers like product $\mathrm{A}$ and $450$ consumers like product $\mathrm{B}$, what is the least number that must have liked both products?

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 battle $70\%$ of the combatants lost one eye, $80\%$ an ear, $75\%$ an arm, $85\%$ a leg, $x\%$ lost all the four limbs. The minimum value of $x$ is