jenny had driven for 2h at a constant speed when road forced to reduce her speed by 10 mp/h for the remaining 1h of 152 mile trip. find her original speed
152 - 10 = 142/2 = 71 mp/h
Can 71 mi/hr be right for the first speed?
71 mi/hr x 2 hrs = 142 miles traveled.
10 mi/hr x 1 hr = 10 miles traveled.
So we have 152 miles traveled in three hours BUT the second speed is not 10 mi/hr less than the original speed. In fact it is 71-10 = 61 mi/hr less. I think this answer is flawed.
You're correct, the answer provided in your previous statement is flawed. Let's go through the problem and solution again to find the correct original speed.
Jenny drove for 2 hours at a constant speed, let's call this speed "v". The distance covered in these 2 hours is equal to 2v.
The remaining time for Jenny's trip was 1 hour, during which her speed was reduced by 10 mph. Let's now calculate the distance covered during this time.
We know that the total distance of the trip is 152 miles. So, the distance covered in the remaining 1 hour is:
152 miles - (2v) miles = 152 - 2v miles.
According to the given information, this distance is equal to the speed during the remaining 1 hour (which is v - 10) multiplied by the time of 1 hour.
(v - 10) * 1 = v - 10 miles.
Now, we can set up the equation:
2v + (v - 10) = 152.
Simplifying,
3v - 10 = 152.
Adding 10 to both sides,
3v = 162.
Dividing by 3,
v = 54.
Therefore, the original speed of Jenny was 54 mph.