Kathy and Cheryl are walking in a fundraiser. Kathy completes the course in 4.8 hours and Cheryl completes the course in 8 hours. Kathy walks 2 miles per hour faster than Cheryl. Find kathy's Speed and cheryl's Speed.

Respuesta :

Answer:

Kathy's speed is equal to [tex]5\ mph[/tex]

Cheryl's speed is equal to [tex]3\ mph[/tex]

Step-by-step explanation:

Let

x-----> Kathy's speed

y----> Cheryl's speed

d----> the distance in miles

t----> the time in hours

s-----> the speed in miles per hour

we know that

The speed is equal to the distance divided by the time

so

[tex]s=d/t[/tex]

solve for the distance d

[tex]d=st[/tex]

In this problem

[tex]x=y+2[/tex] ----> equation A

Kathy's speed

we have

[tex]s=x\ mph[/tex]

[tex]t=4.8\ h[/tex]

substitute in the formula of distance

[tex]d=4.8x[/tex] -----> equation B

substitute equation A in equation B

[tex]d=4.8(y+2)[/tex]

[tex]d=4.8y+9.6[/tex] ------> equation C

Cheryl's speed

we have

[tex]s=y\ mph[/tex]

[tex]t=8\ h[/tex]

substitute in the formula of distance

[tex]d=8y[/tex] -----> equation D

Remember that the distance is the same in both cases

so

equate equation C and equation D and solve for y

[tex]4.8y+9.6=8y[/tex]

[tex]8y-4.8y=9.6[/tex]

[tex]3.2y=9.6[/tex]

[tex]y=3\ mph[/tex]

Find the value of x

[tex]x=y+2[/tex] -----> [tex]x=3+2=5\ mph[/tex]