Originally Posted by

**hugo84** Let A and B be sets in a universe,

with |A ∩ B| = 4

|A U B| = 7

Determine the number of subsets in A U B which contains A ∩ B.

My Solution:

|AUB| = |A| + |B| - |A∩B|

=3+4-4=3

|A∩B|=|A|+|B|-|AUB|

=3+4-3=4

4+3=7

However i think it contradicts the given |A U B| = 7 ,which what i compute = 3.

Also i dont understand what it means by Determine the number of subsets in A U B which contains A ∩ B?? dosent AUB contains A ∩ B arleady?Please enlighten me on how should i solve this question.. thanks