# GMAT-data sufficiency (數學-3)

Of the 75 houses in a certain community, 48 have a patio. How many of the

houses in the community have a swimming pool?

(1) 38 of the houses in the community have a patio but do not have a swimming

pool.

(2) The number of houses in the community that have a patio and a swimming pool

is equal to the number of houses in the community that have neither a

swimming pool nor a patio.

答案B

### 1 Answer

- ThomasLv 61 decade agoBest Answer
A: 有patio; 無pool

B: 無patio; 有pool

X: 有patio; 有pool

Y: 無patio; 無pool

註

A+X: 有patio

B+X: 有pool

所以問題:

A+X = 48

A+X+B+Y = 75

========

(2)

X=Y

=>

A+X+B+Y=(A+X) + (B+X) = 75

因為 A+X =48

所以 B+X = 75-48=27

可以得知, 有 pool 有 27戶

2008-03-27 16:51:38 補充：

至於 (1)

由於只得知

A=38

X=10

B+Y=75-48=27

B=0 or 1 or 2 or .....27

所以,

B+X = 10,11,12,......,37 都有可能