Let's say Miles Carlos drove = x and taook time = t1
Miles Maria drove = y and took time = t2
But the total mile both drove = 233 and took time = 4.4 hrs
So , x + y = 233
t1 + t2 = 4.4
However, speed = distance / time
for Carlos, 55 = x / t1
for Maria, 50 = y / t2
x + y = 233
55 t1 + 50 t2 = 233
t1 + t2 = 4.4
50 t1 + 50 t2 = 220
5 t1 = 13
t1 = 2.6 hrs for Carlos
t2 = 1.8 hrs
Therefore Maria drove 4.4 hrs