What is the purpose of the information in the excerpt from the article ""those old piano blues""?.

Did the universe cool off or get hotter as it expanded after the 'big bang"?

Summarize the work of famous environmental scientists of the past.

17 a tourist was planning a trip by car for travelling at some constant speed for 2.5 hours. however, he found that if he increases the speed by 20 km/h he can cover the same distance in 30 minutes less time than it was planned. what was the planned speed of the tourist, in km/h?