Question

Carlos and Maria drove a total of 233 miles in 4.4 hours. Carlos drove the first part of the trip and averaged 55 miles per hour. Maria drove the remainder of the trip and averaged 50 miles per hour. For approximately how many hours did Maria drive? Round your answer to the nearest tenth if necessary.

Answer 1

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