Given that from a point on a river, two boats are driven in opposite directions, one at 7 miles per hour and the other at 11 miles per hour, to determine how many hours they will be 54 miles apart, the following calculation must be performed :
54 / (11 + 7) = X
54/18 = X
3 = X
Therefore, both boats will be 54 miles apart after 3 hours.
