Answer:
George must run the last half mile at a speed of 6 miles per hour in order to arrive at school just as school begins today
Step-by-step explanation:
Here, we are interested in calculating the number of hours George must walk to arrive at school the normal time he arrives given that his speed is different from what it used to be.
Let’s first start at looking at how many hours he take per day on a normal day, all things being equal.
Mathematically;
time = distance/speed
He walks 1 mile at 3 miles per hour.
Thus, the total amount of time he spend each normal day would be;
time = 1/3 hour or 20 minutes
Now, let’s look at his split journey today. What we know is that by adding the times taken for each side of the journey, he would arrive at the school the normal time he arrives given that he left home at the time he used to.
Let the unknown speed be x miles/hour
Mathematically;
We shall be using the formula for time by dividing the distance by the speed
1/3 = 1/2/(2) + 1/2/x
1/3 = 1/4 + 1/2x
1/2x = 1/3 - 1/4
1/2x = (4-3)/12
1/2x = 1/12
2x = 12
x = 12/2
x = 6 miles per hour
Answer:
Step-by-step explanation:
it's another one of those similar triangles
it's easier to see this one.
t /c = u / b
where
t = 7x + 3
c = 27
u = 35
b = 21
plug in the knowns
7x + 3 / 27 = 35 / 21
7x + 3 = 27 ( 35 / 21 )
7x + 3 = 9 ( 35 / 7 ) ( divided by 3 )
7x + 3 = 9 ( 5) ( 7 into 35 =5 )
7x + 3 = 45
7x = 45 - 3
7x = 42
x = 6
I checked it, the ratio is 1_2/3 :) for both, but you can check it too
B. 273.18 is the correct answer I think.
If Deliah does jumping jacks at a constant rate, this means that she does them at the same pace or you could say that she does the same amount of jumping jacks in a specified amount of time, ie. if you counted how many jumping jacks she did in one minute, it would be same as how many she would complete in the next minute, and the next, and so on.
Now given that she does 184 jumping jacks in four minutes, and she has kept a constant pace throughout, to find out how many she does each minute, we simply need to divide the number of jumping jacks she does in 4 minutes by 4. Thus:
Jumping jacks in 1 minute = Jumping jacks in 4 minutes / 4
= 184 / 4
= 46
Thus, Deliah can do 46 jumping jacks per minute.
Please see the answer here
http://www.wolframalpha.com/input/?i=y%5E-1%20dy%20%2Bye%5E%28cosx%29%20sinxdx%3D0
