For 8 people, the logic is :
(Is my logic OK ?)
Out of 100 people,
-25 did not have PC,
-32 did not have DW
-15 did not have fridge
-20 did not have VC
Hence number of people having all the four are
But is there a loophole in above.
Numbers can not be added as some could be common, but not have 2 or 3 or any of the items.
If you go by probability theory then the answer is 34.68%