Rachel finished 3/4 of the race in 6 hours how long was the entire race

Me because some of question i don’t understand

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Cody started biking to the park traveling 15 mph, after some time the bike got a flat so cody walked the rest of the way, traveling 4 mph. if the total trip to the park took 6 hours and it was 46 miles away, how long did cody travel at each speed? solve using rate times time= distance