数学题：乐乐一家去昆明旅游。他们开车从家里出发，计划12个小时到达，结果前3小时行驶了全程的30%（百分之三十），照这样行驶能提前几小时到昆明？

数学题解答：

12 – 3 ÷ 30% = 2（小时）

其中3 ÷ 30%算出的是照前3小时行驶速度而行完全程的时间。

推荐阅读：
Beyond Infographics: Alternative Visual Content Strategies That 　 7 Keys to Business Success for Young Digital Marketers　 4 Ways to Deepen Engagement with Your Blog Audience　 Attract Tech Talent To Your Small Business With This Expert Advi　 3 Steps To A Better Classifieds Website　 Jailed Saudi Blogger’s Children Plead For His Release　 Chatbots and the Changing Art of Blogging　 Marketing Tips for E-Commerce Websites　 5 Tips for Staying Safe Online　 10 Signs Your Blog is Working