Question

A= {x/x is a factor of 24} B= {y/y is a multiple of 3 y is less than 24} find n[(A-B) U (B-A)]

Answer 1

Solution :

A= {x/x is a factor of 24 }

= { 1,2,3,4,6,8,12,24 }

B= {y/y is a multiple of 3 y is less than 24}

= { 3,6,9,12,15,18,21 }

i ) A - B

= { 1,2,3,4,6,8,12,24 } -

{ 3,6,9,12,15,18,21 }

= { 1,2,4,8,24 }-----( 1 )

ii ) B - A

= { 3,6,9,12,15,18,21 } -

{ 1,2,3,4,6,8,12,24 }

= { 9, 15,18,21 } ----( 2 )

iii ) (A-B) U (B-A)

= { 1,2,4,8,24 } U { 9, 15,18,21}

= { 1,2,4,8,9,15,18,21,24 }

iv ) n[(A-B) U (B-A)]

= 9

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