7th grade MATH
posted by M. .
? reads,"7th place driver had a time that was 18.5 min slower thatn the driver ahead of him(2hr 43min 7sec), what was his time in hrs, min & sec.? What was the diff. btwn 1st and 7th? Calculate the winner's time in hrs. only(answer correct to 3 decimal places). Winners time: 2hrs. 37min. Several more questions like these?
Thanks!

Each minute has 60 seconds.
18.5 minutes = 18 minutes 30 seconds
Add that to 2 hr 43 min 7 seconds for the driver ahead of him, since his time (7th) will be greater.
Subtract 2 hr 37 min from the previous answer for difference between 1st and 7th.
Winner's time = 2 hours and 37 min. There are 60 minutes in an hour. Get minutes as fraction of hour and convert to a decimal.
See if these principles will help you with the other questions. 
75 seconds:2 minutes, as a fraction