If A = 2, ,4, ,5 , , ,B = 7, , ,8, ,9 , then n(A B) is equal to - Vidyadip

MCQ

If $A = \{ 2,\,4,\,5\} ,\,\,B = \{ 7,\,\,8,\,9\} ,$ then $n(A \times B)$ is equal to

A
$6$
✓
$9$
C
$3$
D
$0$

✓

Answer

Correct option: B.

$9$

b
(b) $A × B = {(2, 7), (2, 8), (2, 9), (4, 7), (4, 8), (4, 9), (5, 7), (5, 8), (5, 9)}$

$n(A × B) = n(A) . n(B) = 3 × 3 = 9.$

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