Data Sufficiency

Guys,
please check my thinking



OA B

75 = (have patio)+(have pool)-(have patio and pool)+(do not have patio and pool)
Main stem:
75 = (48)+(have pool)-(have patio and pool)+(do not have patio and pool)
Question: (have pool) = ?

(1)
only patio = 38, therefore (have patio and pool)=10
75 = (38)+(have pool)-(10)+(do not have patio and pool)
Question: (have pool) = ?, we do not know (do not have patio and pool).
INSUFF

(2)
(have patio and pool)=(do not have patio and pool) let it be x
75 = (48)+(have pool)-x+x
75 = (48)+(have pool)
(have pool)=27
SUFF

B


I dont know why, but i fell i am not correct
Fell I became very suspicious