If A = {3, 6, 9, 12, 15, 18, 21}, B = {4, 8, 12, 16, 20}, find (i) D – A

(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, D−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.

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

D – A = {5, 10, 20}

(ii) To find, B−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.

B – C = {4, 8, 12, 16, 20} - {2, 4, 6, 8, 10, 12, 14, 16}

B – C = {20}

(iii) To find, B−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.

B – D =  {5, 10, 15, 20} - {4, 8, 12, 16, 20}

B – D = {4, 8, 12, 16}

(iv) To find, C−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.

C − B = {2, 4, 6, 8, 10, 12, 14, 16} -  {4, 8, 12, 16, 20}

C – B = {2, 6, 10, 14}

(v) To find, D−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. 

 D−B = {5, 10, 15, 20} - {4, 8, 12, 16, 20}

D – B = {5, 10, 15}

(vi) To find, C−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.

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

C – D = {2, 4, 6, 8, 12, 14, 16}

(vii) To find, D−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.

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

D – C = {5, 15, 20}