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:Sorry i have no time to read it all bro
Step-by-step explanation:
In the given question, there are numerous information's already provided. It is important to note then down first. With the help of those given information's the required answer can be easily reached.
Percentage of students that weighed 140 pounds = 75 percent
Then
Percentage of students that weighed more than 140 pounds = (100 - 75) percent
= 25 percent
Total number of students that were weighed = 40 students
Total number of students that weighed more than 140 pounds = (25/100) * 40
= (40/4) students
= 10 students
So the number of students that weighed more than 140 pounds is 10. So the correct option in regards to the given question is option "1".
B = 6
Just factorize the first bracket
The formula is d=C/π.
The diameter is 2 times the radius
The formula for the circumference using the radius is 2πr.
in order to do this backwards, we would have to do 16÷2÷π, but we're not looking for the radius.
Therefore, we take out the ÷2 part, which would be 16÷π
16 is the circumference
16÷π=d
d=C÷π
