Question 103744
Distance = Rate * Time
In this case we know:
Tom's rate is 4 mph slower than Tina. Call these x and x+4, respectively.
We know they traveled for 2 hr 30 min, which is 2.5 hr.
So Tom traveled 2.5x, and Tina traveled 2.5(x+4)=2.5x+10.
We know that at noon they had covered 50 miles in total, part of which was traveled by Tom and part of which was traveled by Tina.
So we know that 2.5x (the distance Tom traveled) + 2.5x + 10 (the distance Tina traveled) = 50.
2.5x + 2.5x + 10 = 50
Combining:
5x + 10 = 50
Subract 10 from both sides:
5x = 40
Divide through by 5:
x = 8
So Tom's speed is 8 mph.
Tina's speed is 4 mph faster, so it is 8+4 = 12 mph.
ALWAYS check!
In this case, substitute the speeds to ensure they covered 50 miles.
2.5*8 = 20 = Tom's distance traveled.
2.5*12 = 30 = Tina's distance traveled.
Check!