David knew he made a mistake when he calculated that Gilda walks 123 miles to the station. Read through David's calculations:

Using d = rt, the distance is the same, but the rate and time are different.
If Gilda misses the train, it means the time t needs 7 more minutes so d = 3(t + 7).
If she gets to the station 5 minutes early means the time t can be 5 minutes less so d = 4(t - 5).
3(t + 7) = 4(t - 5)
3t + 21 = 4t - 20
t = 41
d = rt, so d = 3(41) = 123

Find David's

Do you guys think you could help me through the steps of this. i have been on it f

Question

David knew he made a mistake when he calculated that Gilda walks 123 miles to the station. Read through David's calculations:

    Using d = rt, the distance is the same, but the rate and time are different.
    If Gilda misses the train, it means the time t needs 7 more minutes so d = 3(t + 7).
    If she gets to the station 5 minutes early means the time t can be 5 minutes less so d = 4(t - 5).
    3(t + 7) = 4(t - 5)
    3t + 21 = 4t - 20
    t = 41
    d = rt, so d = 3(41) = 123

Find David's 

Do you guys think you could help me through the steps of this. i have been on it f

jigglypuff314 · Answer

Hello and Welcome to OpenStudy! :)

I'll try to help, but are you sure that's all the information that you were given?
I am not sure where the 3 and 4 came from

anonymous · Answer

yes i will show you the rest of the info.

anonymous · Answer

Gilda walks to the train station. If she walks at the rate of 3 mph, she misses her train by 7 minutes. However, if she walks at the rate of 4 mph, she reaches the station 5 minutes before the arrival of the train. Find the distance Gilda walks to the station.

anonymous · Answer

i need to find davids mistakes

jigglypuff314 · Answer

hmmm
I don't know where the 3 came from in the  3(41) part

anonymous · Answer

Exactly my point. we need to correct his work to the wright answer.

anonymous · Answer

it might have been when she walked at a rate of 3mph

jigglypuff314 · Answer

you don't know the rate that she would be walking to be perfectly on time.

anonymous · Answer

yes i know but i guess you have to find this. its asking for how far it is to the train station

jigglypuff314 · Answer

I don't see anything mathematically wrong with his calculations :/
I would guess that in the final step the rate should not be 3mph

anonymous · Answer

you can just tell that it is incorrect though because i don't believe she will walk 123 miles. that's just logic

jigglypuff314 · Answer

oh wait... I know how to get the correct answer now.
he should have plugged in t = 41
back into   3(t+7)  or  4(t-5)   to get the distance

jigglypuff314 · Answer

I still get an outrageous number
but it works for some reason :/

anonymous · Answer

alright is understand now. Thanks a ton for the help.

jigglypuff314 · Answer

You're Welcome ^_^