SOLUTION: ****Corrected the complete question***** 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 rat

SOLUTION: Corrected the complete question* 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 rat

Question 1029838: ****Corrected the complete question*****
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.
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 mistake in his calculations. Include the correct calculations and solutions.
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Two mistakes.
Time is measured in minutes.
Rate is measured in miles/hour.
You must convert one of them to be consistent.

Answer is the same but the units are now correct.
When you measured distance, you have to use either of the formulas,

If you use , you'll get the wrong answer since and would give you different answers.

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