Downstream DATA:
distance = 12 miles
time = 2 hours
rate = 12/2 = 6 mph
----------------
Upstream DATA:
distance = 12 miles
time = 4 hrs
rate = 12/4 = 3 mph
----
Equations:
Downstream: b + c = 6
Upstream::: b - c = 3
------
Add to get:
2b = 9
b = 4.5 mph (speed of the boat in still water.)
-----
Solve for "c":
b + c = 6
4.5 + c = 6
c = 1.5 mph (speed of the current)
The answer is 1.5 mph
Answer: When they take my phone I take it back when there not looking
About 450 books and articles Euler completed after he lost his sight entirely.
<h3>Who was Leonhard Euler?</h3>
Leonhard Euler was a mathematician from Switzerland. He introduced the fundamentals of graph theory and topology.
His main field of work includes number theory, mechanics, fluid mechanics, and many more.
The life span of Euler was between 1707 and 1783. In the last few years of his life, he lost the eye sight. But the eye sight loss doesn't affect him from doing his work. In his lifespan, he published around 886 books and articles on various fields or science, mathematics and engineering.
After the total blindness, he published more than 450 books and articles.
For more details about Euler, refer to the link:
brainly.com/question/573685
