prep 有趣的一题，共享

sunshuai856

Of the 75 houses in a certain community, 48 have patio. How many of the houses in the community have swimming pool?
1) 38 of the houses in the community have a patio but 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

sunshuai856

顶

sunshuai856

顶

sunshuai856

顶

sunshuai856

x = patio house = 48
y = pool house..........? we need this.
z = patio + pool
n = neither of them

x + y - z + n = 75,

1) z = 48 - 38 = 10.........not suff.

2) as per 2) z = n. (at this point u know B will be the answer)

x + y - z + z = 75
x + y = 75
y = 75 - x = 75 - 48 = 27

2) is answer.

sunshuai856

呵呵，做了2次才做对，真是白痴，anyway，fighting！

hang13

哦 我还以为是选C呢

艾瑞克BA圣诞

哦~~是挺巧妙，乍一看也以为是C

grantchao

very tricky