The average speed in the morning trip is
and the speed in the afternoon trip is ![25{\text{ mile/h}}.](https://tex.z-dn.net/?f=25%7B%5Ctext%7B%20mile%2Fh%7D%7D.)
Further explanation:
The relationship between speed, distance and time can be expressed as follows,
![\boxed{{\text{Speed}} = \frac{{{\text{Distance}}}}{{{\text{Dime}}}}}](https://tex.z-dn.net/?f=%5Cboxed%7B%7B%5Ctext%7BSpeed%7D%7D%20%3D%20%5Cfrac%7B%7B%7B%5Ctext%7BDistance%7D%7D%7D%7D%7B%7B%7B%5Ctext%7BDime%7D%7D%7D%7D%7D)
Given:
A motorist drove 150 miles in the morning and 50 miles in the afternoon.
The time taken to travel is ![5{\text{ hours}}.](https://tex.z-dn.net/?f=5%7B%5Ctext%7B%20hours%7D%7D.)
Explanation:
The average rate in the morning was twice his average rate in the afternoon.
Consider the speed of the person in afternoon be ![x{\text{ miles/hour}}.](https://tex.z-dn.net/?f=x%7B%5Ctext%7B%20miles%2Fhour%7D%7D.)
So speed of the person in the morning is ![2x{\text{ miles/hour}}.](https://tex.z-dn.net/?f=2x%7B%5Ctext%7B%20miles%2Fhour%7D%7D.)
The time taken to 150 miles in the morning can be calculated as follows,
![\begin{aligned}{\text{speed}}&=\frac{{{\text{distance}}}}{{{\text{time}}}}\\2x&= \frac{{150}}{{{t_1}}}\\{t_1}&=\frac{{150}}{{2x}}\\{t_1}&= \frac{{75}}{x}\\\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%7B%5Ctext%7Bspeed%7D%7D%26%3D%5Cfrac%7B%7B%7B%5Ctext%7Bdistance%7D%7D%7D%7D%7B%7B%7B%5Ctext%7Btime%7D%7D%7D%7D%5C%5C2x%26%3D%20%5Cfrac%7B%7B150%7D%7D%7B%7B%7Bt_1%7D%7D%7D%5C%5C%7Bt_1%7D%26%3D%5Cfrac%7B%7B150%7D%7D%7B%7B2x%7D%7D%5C%5C%7Bt_1%7D%26%3D%20%5Cfrac%7B%7B75%7D%7D%7Bx%7D%5C%5C%5Cend%7Baligned%7D)
The time taken to 50 miles in the afternoon can be calculated as follows,
![\begin{aligned}{\text{speed}} &= \frac{{{\text{distance}}}}{{{\text{time}}}}\\x&= \frac{{50}}{{{t_2}}}\\{t_2}&= \frac{{50}}{x}\\\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%7B%5Ctext%7Bspeed%7D%7D%20%26%3D%20%5Cfrac%7B%7B%7B%5Ctext%7Bdistance%7D%7D%7D%7D%7B%7B%7B%5Ctext%7Btime%7D%7D%7D%7D%5C%5Cx%26%3D%20%5Cfrac%7B%7B50%7D%7D%7B%7B%7Bt_2%7D%7D%7D%5C%5C%7Bt_2%7D%26%3D%20%5Cfrac%7B%7B50%7D%7D%7Bx%7D%5C%5C%5Cend%7Baligned%7D)
The total time taken by the person is 5 hours.
![\begin{aligned}t&= {t_1} + {t_2}\\5&= \frac{{75}}{x}+ \frac{{50}}{x}\\5 &= \frac{{75 + 50}}{x}\\x&=\frac{{125}}{5}\\x&= 25\\\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7Dt%26%3D%20%7Bt_1%7D%20%2B%20%7Bt_2%7D%5C%5C5%26%3D%20%5Cfrac%7B%7B75%7D%7D%7Bx%7D%2B%20%5Cfrac%7B%7B50%7D%7D%7Bx%7D%5C%5C5%20%26%3D%20%5Cfrac%7B%7B75%20%2B%2050%7D%7D%7Bx%7D%5C%5Cx%26%3D%5Cfrac%7B%7B125%7D%7D%7B5%7D%5C%5Cx%26%3D%2025%5C%5C%5Cend%7Baligned%7D)
The speed of the person in the afternoon is ![25{\text{ miles/h}}.](https://tex.z-dn.net/?f=25%7B%5Ctext%7B%20miles%2Fh%7D%7D.)
The speed of the person in the morning can be calculated as follows,
![\begin{aligned}{\text{Speed} &= 2 \times 25\\&= 50{\text{ miles/h}}\\\end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%7B%5Ctext%7BSpeed%7D%20%26%3D%202%20%5Ctimes%2025%5C%5C%26%3D%2050%7B%5Ctext%7B%20miles%2Fh%7D%7D%5C%5C%5Cend%7Bgathered%7D)
The average speed in the morning trip is
and the speed in the afternoon trip is ![\boxed{25{\text{ mile/h}}}.](https://tex.z-dn.net/?f=%5Cboxed%7B25%7B%5Ctext%7B%20mile%2Fh%7D%7D%7D.)
Learn more:
1. Learn more about inverse of the functionhttps://brainly.com/question/1632445.
2. Learn more about equation of circle brainly.com/question/1506955.
3. Learn more about range and domain of the function brainly.com/question/3412497
Answer details:
Grade: High School
Subject: Mathematics
Chapter: Speed and Distance
Keywords:Train, twice, fast, downhill, uphill, can go, 2/3 feet, level ground, speed, time, distance, 120 miles per hour downhill, flat land, travel, 45 miles.