To find the answer to this question, we first need to know how many miles the family has gone. We can do this using the formula D = R * T
D = 45 * 2 D = 90
Now we know how many miles the family is in front of the neighbor before he starts driving. Now we need to find how much faster the speed of the neighbor is compared to the family.
60 - 45 = 15, so the neighbor goes 15 mph faster. To find how long it will take for the neighbor to overtake the family, we need to calculate the time it will take for the neighbor to catch up 90 miles. We can do this by dividing 90 by 15 (because that's how much faster the neighbor is).
90/15 is 6, so it will take the neighbor 6 hours to overtake the family.