Let d represent the distance of the destination from the starting point.
After 45 min, Henry has already driven d-68 miles. After 71 min., he has already driven d-51.5 miles.
So we have 2 points on a straight line:
(45,d-68) and (71,d-51.5). Let's find the slope of the line thru these 2 points:
d-51.5 - (d-68) 16.5 miles
slope of line = m = ----------------------- = ------------------
71 - 45 26 min
Thus, the slope, m, is m = 0.635 miles/min
The distance to his destination would be d - (0.635 miles/min)(79 min), or
d - 50.135 miles. We don't know how far his destination is from his starting point, so represent that by "d."
After 45 minutes: Henry has d - 68 miles to go;
After 71 minutes, he has d - 51.5 miles to go; and
After 79 minutes, he has d - x miles to go. We need to find x.
Actually, much of this is unnecessary. Assuming that Henry's speed is 0.635 miles/ min, and knowing that there are 8 minutes between 71 and 79 minutes, we can figure that the distance traveled during those 8 minutes is
(0.635 miles/min)(8 min) = 5.08 miles. Subtracting thix from 51.5 miles, we conclude that after 79 minutes, Henry has (51.5-5.08), or 46.42, miles left before he reaches his destination.
The <u><em>correct answer</em></u> is:
d) People per hour, because the dependent quantity is the people
Explanation:
In this situation, the two quantities are people and hours. These are the two things in this problem we can count or measure.
The independent variable is the one that causes a change, while the dependent variable is the one that <em>gets</em> changed. In this situation, the number of people change every hour; this means the number of people <em>gets</em> changed, which makes it the dependent variable. This means that the independent variable must be time.
Since people is dependent and time is independent, "people per hour" would be the best form of this statement.
Answer: 480 units^2
IN DEPTH EXPLANATION TO HELP YOU FOR FUTURE PROBLEMS:
Front:
b*h/2 = sa
12*5/2 = 30
Front = 30 units^2
Back:
b*h/2 = sa
12*5/2 = 30
Back = 30 units^2
Right:
w*l = sa
14*13 = 182 units^2
Right: 182 units*2
(figures out the length by using
pythagorean theorem)
Left:
w*l = sa
5*14 = 70 units^2
Left: 70 units^2
Bottom:
w*l = sa
12*14 = 168 units^2
ADD ALL THE UNITS:
168 + 70 + 182 + 30 + 30 = 480
