Question

If $A\times B=$ $(2,4),(2,a),(2,5),(1,4),(1,a),(1,5)$, find $B$.

• A. $\{4,2,5\}$
• B. $\{4,a,5\}$
• C. $\{4,1,5\}$
• D. $\{2,a,5\}$

Answer 1

Answer: (B)

$\{4,a,5\}$

$A\times B=\left\{\right(2,4),(2,a),(2,5),(1,4),(1,a),(1,5\left)\right\}$

$B=\{4,a,5\}$

as we know B is a set of all second entries in ordered pair $A\times B$.