Problema Solution

A man travels x km at 8km/h and y km at 20km/h.the the total time is three and half hours .

The total time taken to travel (2x+4)km at 8km and y/3 at 20km/h is 5hours .find x and y.

Answer provided by our tutors

since speed = distance/time => time = distance/speed


A man travels x km at 8km/h and y km at 20km/h.the the total time is three and half hours.


the time he travels x km at 8km/h + the time he travels y km at 20km/h = the total time of 3.5 hours


x/8 + y/20 = 3.5


similar for: the total time taken to travel (2x+4)km at 8km and y/3 at 20km/h is 5 hours


the time he travels (2x+4) km at 8km/h + the time he travels y/3 km at 20km/h = the total time of 5 hours


(2x + 4)/8 + (y/3)/20 = 5


(x + 2)/4 + y/60 = 5


by solving the system of equations


x/8 + y/20 = 3.5

(x + 2)/4 + y/60 = 5


we find


x = 16 km


y = 30 km


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