Data Sufficiency (DS) | Re: Of the 75 houses in a certain community, 48 have a patio. How many of

Bunuel

How can we preclude that there is no third set we have to consider?
Since the statement does not state that only a pool or a patio are possible, can we always assume that there is no third set involved, when we solve such a question?
Because if there was a third set involved, we must use the formula
Total = A+B+C-[-two Group overlaps] + all three + neither. Then statement 2 would be insufficient, since we dont know the other variables.
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