Question

Esmeralda went to the mall traveling 9 mph and returned home traveling 12 mph. If the total trip took 7 hours, how long did Esmeralda travel at each speed?

Answer 1

r u in clas right now

Answer 2

no?

Answer 3

This makes no sense. How many minutes did she take AT the mall?

Answer 4

i think it is asking how long did it take to get there at the speed of 9pmh and home at the speed of 12mph with a total round trip time of 7 hours

Answer 5

ok..........

Answer 6

argh! this is so frustrating. I know time=distance times speed, but...it's asking how long it took to get there and throwing in 2 speeds! :(

Answer 7

with no distance...

Answer 8

Math Logic: The mall is a 7 hour round trip.
My Logic: WHY WOULD ANYONE DRIVE A 7 HOUR ROUND-TRIP TO GO TO THE MALL?????

Answer 9

That's what I spent 8 minutes wondering...

Answer 10

lol

Answer 11

Personally, I have to drive 2 hrs to the nearest town (96 miles) and have never been in a mall! lol

Answer 12

Let's stay on topic, please.

Answer 13

Rate (times) Time (equals) Distance... R*T=D

Answer 14

ok, so if there are 2 times, it would be 9+12? rate is 7? idk..

Answer 15

There is one distance: That to the mall (or, that from the mall). Call it d.

Assume that d is measured in miles.

Then the time required to drive to the mall is \[t _{1}=\frac{ d }{ 9\frac{ miles }{ hour }}\]

Answer 16

and the time req'd to return, at 12 mph, is \[t _{2}=\frac{ d }{\frac{ 12~miles }{ hour } }\]

Answer 17

>>

Answer 18

t sub 1 and t sub 2 MUST add up to 7 hours.

Write this equation.

There is not enough info given to actually solve for t sub 1 and t sub 2, that is, to obtain numerical values. Or is there some bright person out there who can do that?

Answer 19

Note that t sub 2 MUST equal 7 hours - t sub 1.

We don't know distance d, but we do know that the distances traveled are equal.

Thus:\[d=(9mph)(t _{1})=(12mph)(t _{2})\]

Answer 20

still not understanding how to get the answer :(

Answer 21

I think I get it.

Answer 22

we can substitute \[7 hours - (12 mph)-t _{1}\]
for t sub 2.

This eliminates t sub 2, and we therefore have one equation for t sub 1. Find t sub 1.

Answer 23

Please finish this solution, checking back with the original equation to ascertain that you have done everything that was called for.

Answer 24

correction no need to find 2d
find only d

Answer 25

4hours at 9mph and 3 hrs at 12mph!

Answer 26

yay!

Answer 27

correct.

Answer 28

So cool! Keep up the good work.