Question

Whitney left school and drove 7 miles to meet her mother at a restaurant. Her mother left at the same time and drove 8 miles, traveling 5 mi/h faster than her daughter. If the two arrived at the restaurant at the same time, what was Whitney’s speed?

a 30 mi/h
b 35 mi/h
c 46 mi/h
d 51 m/h

Answer 1

@johnweldon1993 can u help?

Answer 2

if you could not solve what i gave i would of helped

Answer 3

sorry

Answer 4

We know that Distance = rate times time

\[\large D = rt\]
or we can write this in terms of time (you'll see why in a few)
\[\large t = \frac{d}{r}\]
The time Whitney traveled we'll write as

\[\large t_w = \frac{d_w}{r_w}\]

and the time for her mother lets write as

\[\large t_m = \frac{d_m}{r_m}\]

We also know that the travel took the same time for both...so

So what we now have is

\[\large t_w = t_m\]

lets plug in what we know..and that is

\[\large \frac{d_w}{r_w} = \frac{d_m}{r_m}\]

so...we know Whiteny trveled 7 miles....and the other traveled 8

\[\large \frac{7}{r_w} = \frac{8}{r_m}\]

lets say whitney traveled 'x' mph and her mother would have done x + 5 (since she traveled 5mph faster than her daughter)

so

\[\large \frac{7}{x} = \frac{8}{x + 5}\]

Now we just cross multiply and solve for 'x'

Answer 5

ok

Answer 6

Let me know what you get :)

Answer 7

ok hold on

Answer 8

35?

Answer 9

Perfect!

Answer 10

so thats the answer

Answer 11

indeed^ :)

Answer 12

thanks XD

Answer 13

lol no problem :P