word problem

xc630

Junior Member
Joined
Sep 1, 2005
Messages
164
Hi am having trouble solving this. I don't know how to set it up. Thanks for any help.

Kelly and Chris are shopping in the city. Chris leaves for home in his car at 3:00 traveling at 48 miles per hour, but Kelly is engrossed in a shoe store and doesn't leave until 3:15. If she drives at 66 miles per hour, how long after she leaves does she catch up with Chris?
 
same distance, and:
.......@ 48............t
.......@ 66............t-15

speed = distance / time

take over.
 
Hello, xc630!

Kelly and Chris are shopping in the city.
Chris leaves for home in his car at 3:00 traveling at 48 miles per hour,
but Kelly is engrossed in a shoe store and doesn't leave until 3:15.
If she drives at 66 miles per hour, how long after she leaves does she catch up with Chris?
Try to diagram the problem.

Chris leaves at 3:00 and drives at 48 mph.
. . He has a 15-munute (¼ hour) head start.
. . In that ¼-hour, Chris has driven: \(\displaystyle \frac{1}{4}\,\times\,48\:=\: 12\) miles.
Code:
. . . . . .12 . . . . 48t
. . . *---------* - - - - - - ->|

. . . * - - - - - - - - - - - ->|
. . . . . . . .  66t

In the next \(\displaystyle t\) hours, Chris drives an additional \(\displaystyle 48t\) miles.
At the same time, Kelly drive \(\displaystyle 66t\) miles.

Their total distances are equal.
. . Hence, we have: \(\displaystyle \;66t\:=\:48t\,+\,12\) . . . there!

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Careful, Denis . . .

Of course, you didn't mean: \(\displaystyle \;t\,-\,15\) hours.
 
soroban said:
Careful, Denis . . .
Of course, you didn't mean: \(\displaystyle \;t\,-\,15\) hours.
"........ and doesn't leave until 3:15."
so didn't think I needed to clarify...

My turn:
"Try to diagram the problem."
"diagram" is not a verb :shock:
 
Denis said:
"Try to diagram the problem."
"diagram" is not a verb
You never had to diagram sentences back in your grammar classes...?

Eliz.
 
bambi said:
where do I start having trouble.
1) We have no idea where you're having trouble. You'll have to tell us.

2) Please tell us by starting a new thread; "hijacking" somebody else's thread is considered poor netiquette.

Thank you.

Eliz.
 
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