Answer: the speed of the current is 9 mph.
Step-by-step explanation:
Let x represent the speed of the current.
A boat can travel 21 mph in still water. If it travels 270 miles with the current. It means that the total speed with which the boat travelled with the current is (21 + x) mph.
Time = distance/speed
Time spent by the boat in travelling 270 miles is
270/(21 + x)
In the same length of time, it travels 108 miles against the current. It means that the total speed with which the boat travelled against the current is (21 - x) mph.
Time = distance/speed
Time spent by the boat in travelling 108 miles is
108/(21 - x)
Since the time is the same, then
270/(21 + x) = 108/(21 - x)
270(21 - x) = 108(21 + x)
5670 - 270x = 2268 - 108x
108x + 270x = 5670 - 2268
378x = 3402
x = 3402/378
x = 9
Answer:
c
Step-by-step explanation:
Since it is a ratio to those who get bonus and don't, it is 24:80.
you must add 24+56 to get total amount of employees.
24+56=80
therefore, the answer is 24:80
Suppose the students who scored 85 and 90 on the math test take the test again and score 95. How many stars would you have to add to the picturegraph next to 95?
10
Answer:
A triangle has sides of lengths 9,7, and 12 is not a right triangle .
You're lucky that I was able to do this :)
The answer is 
