How many minutes is it before 12at noon if 90 minutes ago it was four times as many minutes past 9 a. m. ?

admin2011-01-05 58

问题 How many minutes is it before 12at noon if 90 minutes ago it was four times as many minutes past 9 a. m. ?

选项

答案72

解析 (设是中午12点以前x分钟。根据题意可得此方程式：x=4[12×60一(90+x)一9×60]解得X=72)

转载请注明原文地址:https://kaotiyun.com/show/yJVK777K

C类竞赛（非英语专业本科）

相关试题推荐

随机试题

最新回复(0)