यदि `A={3,6,9,12,15,12,18,21}, B={4,8,12,16,20}, C={2,4,6,8,10,12,14,16}`
`D={5,10,15,20}` तो निम्नलिखित को ज्ञात कीजिएः
(i) `A-B` (ii) `A-C`
(iii) `A-D` (iv) `B-A`
(v) `C-A` (vi) `D-A`
(vii) `B-C` (viii) `B-D`
(ix) `C-B` (x) `D-B`
(xi) `C-D` (xii) `D-C`

Explanation

(i) `A={3,5,9,12,15,18,21}` तथर `B={4,8,12,16,20}`
`A-B={x:x epsilonA` परंतु ` x !inB}`
`={3,6,9,15,18,21}`
अतः `A-B={3,6,9,15,18,21}`
(ii) `A={3,6,9,12,15,18,21}`
तथा `C={2,4,5,8,10,12,14,16}`
`A-C={x:x epsilonA` परंतु `x!in C}`
अतः `A-C={3,9,15,18,21}`
(iii) `A={36,9,12,15,18,21}` तथा
`D={5,10,15,20}`
`A-D={x:x epsilonA` परंतु `x !in D}`
अतः `A-D={3,6,9,12,18,21}`
(iv) `A={3,6,9,12,15,18,21}`
तथा `B={4,8,12,16,20}`
`B-A={x:xepsilonB` परंतु `x !inA}`
`={4,8,16,20}`
अतः `B-A={4,8,16,20}`
(v) `A={3,6,9,12,15,18,21}` तथा `C={2,4,6,8,10,12,14,6}`
`C-A={x:x epsilon` परंतु `x !inA}`
`={2,4,8,10,14,16}`
अतः `C-A={2,4,8,10,14,16}`
(vi) `A={3,5,9,12,15,18,21}`
तथा `D={5,10,15,20}`
`:.D-A={x:x epsilon` परंतु `x!inA}`
`={5,10,20}`
अतः `D-A={5,10,20}`
(vii) `B={4,8,12,16,20}` तथा
`C={2,4,5,l8,10,12,14,16}`
`B-C={x:x epsilonB` परंतु `x!inC}`
`={20}`
अतः `B-C={20}`
(viii) `B={4,8,12,16,20}` तथा `D={5,10,15,20}`
`B-D={x:x epsilonB` परंतु `x !inD}`
`={4,8,12,16}`
अतः `B-D={4,8,12,16}`
(ix) `B={4,8,12,15,20}` तथा
`C={2,4,6,8,10,12,14,16}`
`C-B={x:x epsilonC` परंतु `x!inB}`
`={2,6,10,14}`
अतः `C-B={2,5,10,14}`
(x) `B={4,8,12,15,20}` तथा `D={5,10,15,20}`
`D-B={x:x epsilonD` परंतु `x !in B}`
`={5,10,15}`
अतः `D-B={5,10,15}`
(xi) `C={2,4,6,8,10,12, 14,16}` तथा
`D={5,10,15,20}`
`C=D={x:x epsilonC` परंतु `x !inD}`
`{2,4,5,8,12,14,16}`
अतः `C-D={2,4,6,8,12,14,16}`
(xii) `C={2,4,6,8,10,12,14,16}` तथा `D={5,10,15,20}`
`:.D-C={x:x epsilonD` परंतु `x!inC}`
`={5,15,20}`
अतः `D-C={5,15,20}`