- Ice is colder in temperature than water
- A waterfall contains water
- A glacier is made of ice
- So, the glacier has the colder water

So, the glacier has the colder water
Q: A mountain with a melting glacier has a stream with a waterfall. The waterfall fills a lake at the base of the mountain. Where is the water coldest?
Context:
- Ice is colder in temperature than water 
- A waterfall contains water 
- A glacier is made of ice