Question

if Q ={1,2,3.....40} and A={x:x is a factor of 42} then write n(A)​

Answer 1

A = { 2,3,7 }

Therefore, n(A) = 3

Hope you got it,

Thanks

Answer 2

$Given \: Q = \{ 1,2,3,\ldots 40\}$

$and \: A = \{ x:x \:is \:a \: factor \: of \: 42 \}$

$i ) A = \{ 1,2,3,6,7,14,21,42\}$

$Cordinal \: number \:of \: A = n(A)$

$= Number \:of \: elements \: in \:set \: A$

$= 8$

$ii) Q = \{ 1,2,3,\ldots 40\}$

$Cordinal \: number \:of \: Q = n(Q)$

$= Number \:of \: elements \: in \:set \: Q$

$= 40$

Therefore.,

$\red{ n(A)}\green {=8}$

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