Question 8062
At 24 mph, Marta ought to consider competing in the Tour de France.

Using the formula: d = rt (distance = rate X time)

For Marta: d1 = (r1)(t1) = 24(t1)
For John: d2 = (r2)(t2) = 48(t2)

But Marta's time is 2 hours longer than John's time, so t1 = t2+2.
And when John catches up with Marta, they will both have traveled the same distance, so, d1 = d2

d2 = d1
48(t2) = 24(t2+2)
48t2 = 24t2 + 48
24t2 = 48
t2 = 2 and t1 = t2+2 = 4

Now Marta leaves at 9:00 am and takes 4 hours while John leaves at 11:00 am and takes 2 hours.

So they will meet up at 9:00 am + 4 hours = 1:00 pm or
11:00 am + 2 hours = 1:00 pm.