a. Two girls are sharing a cold chocolate milk, as in the picture. How long do you think it will take them to drink all the milk? How long would it take if each girl had her own glass and half the milk? Can you see a problem when the girls drink from a common glass?
![745_glass.png](https://secure.tutorsglobe.com/CMSImages/745_glass.png)
b. What is going on in this picture of the East Texas oil field in 1919? Can you see the problem?
![1247_Texas.png](https://secure.tutorsglobe.com/CMSImages/1247_Texas.png)
c. Why did we put these two questions together?