Plz it takes mark 1 hour to get to work each day. mark drives from home 20 minutes to the train station at a constant rate of 42 mph. he then takes the train, traveling at a constant 60 mph, the remaining distance to work. how far does mark live from his work place?

It takes 1 hour to get to work.

It takes 20 minutes to get to the train station, and the rest of the trip is spent on the train that takes him to work.  That means he is on the train for 40 minutes.

20 minutes is equal to 1/3 hour and 40 minutes is 2/3 hour

So from home to train station:

1/3 hour * 42mph = 14 miles

And from train station to work:

2/3 hour * 60mph = 40 miles

So how far does Mark live from his work place?

14 + 40 = 54 miles

your answer would be 12