SAT Word Problem

Question

Trey and his mom stopped at a railroad crossing to let a train pass. As the train began to pass, Trey counted 6 cars in the first 10 seconds. It took the train 2 minutes and 45 seconds to clear the crossing at a constant speed. Which of the following was the most likely number of cars in the train?

Answer 1

Okey, each 10 secs 6 cars.

2 (60 secs) + 45 secs = 165 secs total time .

165/ 10 = 16 +.5

16 times 6 cars = 96 cars

.5 times 6 cars = 3 cars

Total= 99 cars in the train .....the most like number is 100 cars

Answer 2

Clearly, for every  seconds,  cars pass. It's more convenient to have everything in seconds:  minutes and  secondsseconds. We then set up a ratio: