In order to determine the number of miles Molly drove, proceed as follow:
Subtract 1/3·180 and 1/6·180 to 180:
1/3·180 = 180/3 = 60
1/6·180 = 180/6 = 30
180 - 60 - 30 = 90
90 miles is the distance to drive after Jane and Mark drove 1/3 and 1/6 of the total trip.
next, divide the previous result by 2:
90/2 = 45
45 is the distance Molly and Isaac drive to complete the trip
Hence, the number of miles Molly drove was 45 miles
