Benjamin H. answered  01/15/21
Math and Science Made Simple! Experienced, Knowledgeable Tutor
To solve this question, we can use a system of equations.
If we say that A is the speed with which Albert raced and B is the speed with which Bernhard raced, we find that A = 4B because Albert raced 4 times faster than Bernhard. If A and B were measured in miles per hour, then we could say that B*h = 30 because the speed multiplied by time (h in hours) will give us the distance he traveled. Similarly, we say that A*(h-3) = 48 because Albert traveled 48 miles in 3 hours fewer than Bernhard.
This gives us three equations:
- A=4B
 - Bh=30
 - A(h-3)=48
 
Now we can solve for our unknown values:
First, plug-in 4B from our first equation into A in our third equation: 4B(h-3)=48
Next, distribute the 4B: 4Bh - 12B = 48
Next, plug-in the value of Bh: 4(30) - 12B = 48
Next, simplify and solve for B: 120 - 12B = 48 -> 120 - 48 = 12B -> 72 = 12B -> B = 6
Next, find A using the first equation and plugging in B: A=4(6)=24 -> A=24
Finally, find h using the second equation and plugging in B: (6)h = 30 -> h = 5
Albert raced at 24 mph and Bernhard raced at 6 mph. Bernhard raced for 5 hours and Albert raced at 3 hours fewer than that, so Albert raced for 2 hours.
Let me know if you have any questions!