CAT (QA) PYQs

For two sets $A$ and $B$, let $A \Delta B$ denote the set of elements which belong to $A$ or $B$ but not both. If $P=\{1,2,3,4\}, Q=\{2,3,5,6\},, R=\{1,3,7,8,9\}, S=$ $\{2,4,9,10\}$, then the number of elements in $(P \Delta Q) \Delta(R \Delta S)$ is

In a class of $100$ students, $73$ like coffee, $80$ like tea and $52$ like lemonade. It may be possible that some students do not like any of these three drinks. Then the difference between the maximum and minimum possible number of students who like all the three drinks is

A club has $256$ members of whom $144$ can play football, $123$ can play tennis, and $132$ can play cricket. Moreover, $58$ members can play both football and tennis, $25$ can play both cricket and tennis, while $63$ can play both football and cricket. If every member can play at least one game, then the number of members who can play only tennis is