Can someone please explain how im supposed to do this? Its like a 2 week late assignment and i wasn't in class when it was assigned

The following division is being performed using multiplication by the reciprocal find the missing numbers is 5/12 divided by x/3 equals 5/12 times x/10 equals 1/x

Two airplanes start at the same place and travel in opposite directions,one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?

The evening newspaper is delivered at a random time between 5: 30 and 6: 30 pm. dinner is at a random time between 6: 00 and 7: 00 pm. each spinner is spun 30 times and the newspaper arrived 19 times before dinner. determine the experimental probability of the newspaper arriving before dinner.