GMAT数学题,求救
问题描述：
GMAT数学题,求救
a certain culture of bacteria quadrupled every hour.if a container with these bacteria was half full at 10:00am,at what time was it one-eight full?
但是答案上写是凌晨2点啊～为什么呢?
答
细菌数翻四倍需要1小时
半满时是10点,
1小时前,9点：1/2 处以4 =1/8
答案：9点的时候八分之一满