If A = {3, 6, 9, 12, 15, 18, 21}, B = {4, 8, 12, 16, 20},C = {2, 4, 6, 8, 10, 12, 14, 16}, D = {5, 10, 15, 20}; find

(i) Given that,

A = {3, 6, 9, 12, 15, 18, 21}, B = {4, 8, 12, 16, 20},

C = {2, 4, 6, 8, 10, 12, 14, 16}, D = {5, 10, 15, 20}

To find, A−B

The difference of the sets A and B in this order is the set of elements which belong to A but not to B.

A − B = {3, 6, 9, 12, 15, 18, 21} - {4, 8, 12, 16, 20}

A – B = {3, 6, 9, 15, 18, 21}

(ii) To find, A−C

The difference of the sets A and B in this order is the set of elements which belong to A but not to B.

A − C = {3, 6, 9, 12, 15, 18, 21} -  {2, 4, 6, 8, 10, 12, 14, 16}

A – C = {3, 9, 15, 18, 21}

(iii) To find, A−D

The difference of the sets A and B in this order is the set of elements which belong to A but not to B.

A − D = {3, 6, 9, 12, 15, 18, 21} - {5, 10, 15, 20}

A – D = {3, 6, 9, 12, 18, 21}

(iv) To find, B−A

The difference of the sets A and B in this order is the set of elements which belong to A but not to B.

B− A = {4, 8, 12, 16, 20} - {3, 6, 9, 12, 15, 18, 21}

B – A = {4, 8, 16, 20}

(v) To find, C−A

The difference of the sets A and B in this order is the set of elements which belong to A but not to B.

C − A = {2, 4, 6, 8, 10, 12, 14, 16} - {3, 6, 9, 12, 15, 18, 21}

C – A = {2, 4, 8, 10, 14, 16}