GMAT一道数学题
问题描述：
GMAT一道数学题
On monday,a certain animal shelter housed 55 cats and dogs.By Friday,exactly 1/5 of the cats and 1/4 of the dogs had been adopted; no new cats or dogs were brought to the shelter during his period.What is the greatest possible number of pets taht could have been adopted from the animal shelter between Moday and Friday?
答
由题意知,猫和狗共55只,猫的只数是5的倍数,狗的只数是4的倍数.故设猫有5x只（其中x属于正整数）,狗有4y只（其中y属于正整数）且5x+4y=55由上得：x、y的正整数组合只有两种：x=3,y=10或者x=7,y=5因此原有的动物数量有...