Question

Ayshab walked x miles at 4 mph.
She then walked 2x miles at 3 mph.
Find Ayshab's average speed for the whole journey.
Give your answer as a mixed number.​

Answer 1

Answer: Ayshab's average speed for the whole journey =  $3\dfrac{3}{11}\text{ mph}$

Step-by-step explanation:

Formula: Speed = $\dfrac{Distance}{Time}$

i.e. Time = $\dfrac{Distance}{Speed}$

If Ayshab walked x miles at 4 mph, then time taken by him = $\dfrac{x}{4}$ hours

If she then walked 2x miles at 3 mph, then time for this period = $\dfrac{2x}{3}$ hours

Average speed = $\dfrac{Total \ distance}{Total\ time}$

$=\dfrac{x+2x}{\dfrac{x}{4}+\dfrac{2x}{3}}\\\\\\=\dfrac{3x}{x(\dfrac{1}{4}+\dfrac{2}{3})}\\\\\\=\dfrac{3}{\dfrac{3+8}{12}}\\\\\\=\dfrac{3\times12}{11}\\\\=\dfrac{36}{11}\\\\=3\dfrac{3}{11}\text{ mph}$

Hence, Ayshab's average speed for the whole journey =  $3\dfrac{3}{11}\text{ mph}$

Answer 2

Ayshab's average speed for the whole journey is 36/11 mph and this can be determined by using the formula of average speed.

Given :

• Ayshab walked x miles at 4 mph.
• She then walked 2x miles at 3 mph.

The formula of speed is given by:

$\rm Speed = \dfrac{Distance }{Time}$

$\rm Time = \dfrac{ Distance}{Speed}$

Now, the time taken by Ayshab to walk x miles at 4 mph is :

$\rm t_1 = \dfrac{x}{4}$

Now, the time taken by Ayshab to walk 2x miles at 3 mph is:

$\rm t_2 = \dfrac{2x}{3}$

Now, the average speed is given by the formula:

$\rm Avg. \; Speed = \dfrac{Total \;Distance}{Total \; Time}$

                  $=\dfrac{x+2x}{\dfrac{x}{4}+\dfrac{2x}{3}}$

                  $= \dfrac{36}{11}$

Ayshab's average speed for the whole journey is 36/11 mph.

For more information, refer to the link given below:

https://brainly.com/question/12577966