Question

$19$ boys turn out for baseball. Of these, $11$ are wearing baseball shirts and $14$ are wearing baseball pants. There are no boys without one or the other. The number of boys wearing full uniform is

• A. $8$
• B. $6$
• C. $5$
• D. $3$

Answer 1

The correct option is B $6$

$n(A\cup B)=n\left(A\right)+n\left(B\right)-n(A\cap B)$
$19=11+14-n(A\cap B)orn(A\cap B)=6$