## subset and proper subset

Let 's Consider a set A where A={1,2,3}

Can anyone tell me
1>no of subsets of A
2>no of proper subsets of A

Regards,
Asit
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 Quote by lipun4u Let 's Consider a set A where A={1,2,3} Can anyone tell me 1>no of subsets of A 2>no of proper subsets of A Regards, Asit
What have you tried already? If you know the definition of subset, it should be easy enough to make a list of all the subsets and then count them. There is also a very simple formula relating the number of subsets of a given set to its cardinality.

After you answer part 1, part 2 is simply the number of subsets of A minus the number of those sets which are not proper subsets. (what is the definition of proper subset?)
 i know the asnwer if A has three elements, proper subset of A will be 7 becoz all the subsets will be Null,{1},{2},{3},{1,2},{2,3},{1,3} subsets of A will be 8 BY INCLUDING {1,2,3} I asked it, becoz i m not sure ab it. Am i correct ab it ??

## subset and proper subset

the formula for the cardinality of the powerset is 2^(cardinality of the set) hence the number is 8 not 7
 i m saying ab proper subset not subset....

 Quote by lipun4u i know the asnwer if A has three elements, proper subset of A will be 7 becoz all the subsets will be Null,{1},{2},{3},{1,2},{2,3},{1,3} subsets of A will be 8 BY INCLUDING {1,2,3} I asked it, becoz i m not sure ab it. Am i correct ab it ??
Yes, that's correct.

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