Page 107 - Mathematics Class - XI

Now write {1, 2, 3, 4, 5} on circle shown in cutout of fig. (c-ii) and {2, 3, 5, 7, 9} on circle shown in cutout
of fig. (c-iii). as shown in fig. (d).

7. Now take cutout of squared cardboard and paste coloured square paper on it and paste the cutout obtained
as in fig. (c-i) and mark as P and Q.

8. Take two piece of wire/threads and paste the cutout obtained after fig. (e) the end of thread so that the
cutouts are moveable.

P Q ∩

1 2 2 7
3 3
4 5 5 9

Fig. (d) Fig. (e)

DEMONSTRATION
According to the arrangement shown in fig (f), as we roll the thread at the both end we get the required shape.

P Q ∩

1 2 2 7
3 3
4 5 5 9

Fig. (f)

Here, Set P = {1, 2, 3, 4, 5} and Set Q = {2, 3, 5, 7, 9}
Then P ∩ Q = {2, 3, 5} as shown in fig (g)

P Q ∩

1 2 7
3
4 5 9

Fig. (g)

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