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 - 20t = 41d = rt, so d = 3(41) = 123find david's mistake in his calculations. in two or more complete sentences, explain his mistake. include the correct calculations and solutions in your answer.