To solve this problem, let us first assign the variables. Let us say that the trip when driving is denoted by 1, while when taking the train is denoted by 2.
So that we have variables of:
v1 or v2 = v = velocity of the trip
d1 or d2 = d = distance of the trip
t1 or t2 = t = time taken during the trip
The formula relating the three variables v, d and t is given as:
d = v t
Since the distance for each trip is equal therefore d1 = d2, so:
v1 t1 = v2 t2
It was also given that:
v2 = v1 + 48
Therefore:
v1 (36) = (v1 + 48) (20)
36 v1 = 20 v1 + 960
16 v1 = 960
v1 = 60 miles / hr
Therefore the distance is:
d1 = d = v1 t1
d = (60 miles / hr) (36 minutes) (1 hr / 60 minutes)
d = 36 miles
Therefore Fritz has to travel 36 miles going to work.
