数学题：要将糖和水按5：100的比配制成糖水，那么40克的糖需要多少克水？

数学题解答：这题可以正比例知识列方程解答。

设需要x克水。

5:100 = 40:x

5x = 100×40

5x=4000

x=800

答：40克糖需要800克水。

推荐阅读：
Social Media is Dying. Here are 3 Ways to Hack it for More Traff　 5 Skills All Successful Content Writers Have Mastered　 Blogging for Dummies in 2019: The Only Cheat Sheet You Need　 Are Readers Reaching Your Call To Action?　 How to Manage a Content Marketing Plan for Your Blog　 4 Simple Techniques To Bring Your Dead Blog Back To Life　 How to Earn Bitcoin Through Blogging　 5 PayPal Alternatives for Bloggers and Solopreneurs　 Can WordPress Make Other E-commerce Platforms Obsolete?　 How to Start a Food Blog (A Step-By-Step 2019 Guide)