Answer: the speed of the current is 0.6 mph
Step-by-step explanation:
Let x represent the speed of the current.
James is kayaking. He can row 3 mph in still water. If he can travel 6 miles downstream. Assuming he went with the current, it means that his total speed while travelling downstream is (3 + x)
Time = distance/speed
Time taken to travel downstream is
6/(3 + x)
In the same amount of time, he can travel 4 miles upstream. Assuming he went against the current, it means that his total speed while travelling downstream is (3 - x). Time taken to travel upstream is
4/(3 - x)
Since the time is the same, then
6/(3 + x) = 4/(3 - x)
Cross multiplying, it becomes
6(3 - x) = 4(3 + x)
18 - 6x = 12 + 4x
4x + 6x = 18 - 12
10x = 6
x = 6/10
x = 0.6 mph
So, she has 3hrs to grade all papers, for 35 students.. alrite.
the first 5, she does them in 30minutes.. what's the speed rate? well, 5/30 or 1/6
now, she has still 2 hours and a half, or 150 minutes, to do the remaining 30 papers... she has to work at a rate of 30/150 then... which is 1/5 simplified.
now if we take 1/6 as the 100%, what is 1/5 in percentage then?

so 1/5 is 120% in relation to 1/6... meaning the rate of 1/5 she needs to move through, namely 1 paper every 5 minutes, is 20% faster than 1/6.
Micah was asked to add the following expressions:

First, he combined like terms in the numerator and kept the common denominator
First step is correct. He added the like terms in the numerator, because the denominators are same.

So he got , 
In the next step, he cannot cancel out x^2 from the top and bottom . Because x-4 and 3x+2 are added with x^2
If we have x^2 is multiplied with other terms at the top and bottom , then we can cancel out x^2.
So Micah added the expression incorrectly. Final answer is not correct.
C. Tom is incorrect. Maureen earns $67,685.