Prep-T1-Q61

[Godiva[origen]]

61. 5157-!-item-!-187;#058&004472
Of the 60 animals on a certain farm, 40 are either pigs or cows. How many of the animals are cows?

(1) The farm has more than twice as many cows as it has pigs.

(2) The farm has more than 12 pigs.

想不通這題.....
題目說 more than 的話怎麼得出幾支牛...?

[scottkidd]

題目有說有40隻不是豬就是牛，
條件1說牛比豬的兩倍還多；條件2說，豬多於12隻

這樣合併條件1、2， 3x最接近40就是39，x=13，就可以算出來啦！

[chris8888]

根據(1), 列出式子 pigs = x
pigs = x
cows = 2x + 1
x + (2x + 1) = 40 有很多排列組合, 所以未解

(2). pigs假設為13,
13 + (26 + 1) = 40
14 + (28 + 1) = 43 暴了, 超出題目的限制

[Godiva[origen]]

thanks!