Every car at a certain dealership is either a convertible,a sedan,or both.If one-fifth of the convertibles are also seda
问题描述：
Every car at a certain dealership is either a convertible,a sedan,or both.If one-fifth of the convertibles are also sedans and one-third of the sedans are also convertibles,which of the following could be the total number of cars at the dealership?
(A) 28 (B) 29 (C) 30 (D) 31 (E) 32
求地道翻译和完整解题思路及过程
答
一家店里有三种车:敞篷车,轿车和敞篷轿车.
如果1/5的敞篷车也正好是轿车,而1/3的轿车也正好是敞篷车
那么下面哪个数会是店里车的总数.
设敞篷车有x辆,轿车有y辆.
则x/5=y/3
由等比的知识得:x/5=y/3=x+y/8
故总数一定是8的倍数.
故选E