Answer:
- 3 hours
- 1 hour 45 minutes
- 300 miles
Step-by-step explanation:
1. The trains are moving toward each other at a total speed of 50 +20 = 70 miles per hour. Together, they cover the 210 mile distance in ...
time = distance/speed
time = 210 mi/(70 mi/h) = 3 h
The trains collide after 3 hours.
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2. The fly is closing with the freight train at a speed of 100 +20 = 120 miles per hour. Together, the fly and the train cover the initial 210 mile distance in ...
(210 mi)/(120 mi/h) = 7/4 h = 1 hour 45 minutes
The fly first meets the oncoming freight train after 1 h 45 min.
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3. The fly is flying for all three hours before the trains collide, so, at 100 miles per hour, will fly 300 miles.
Answer:
x = 3
y = 8
Step-by-step explanation:
Since it gives you x, you need to plug in the number given for it into the equation:
y = 3x - 1
y = 3(3) - 1
y = 9 - 1
y = 8
So now you have, x = 3 and y = 8
Answer:
All values are identical.
Step-by-step explanation:
We are given the following in the question:
If the standard deviation of a set of data is zero.
Then, all the values in data are identical.
This can be shown as:
Let all the terms in data be x.
Formula:
where
are data points,
is the mean and n is the number of observations.
Sum of squares of differences =


Thus, the correct answer is
All values are identical.
Answer:
Square I think
Step-by-step explanation: