Question

Two trains leave towns 912 kilometers apart at the same time and travel toward each other. One train travels 12

Answer 1

Answer:

Step-by-step explanation:

Remark

The two trains are travelling towards each other. That means that their total distance = 912 km. Neither one has gone that distance by itself. The effect this has on the question is that you add the two rates multiplied by time.

Givens

r1 = x

r2 = x + 12

t = 3 hours

d = 912 km

Equation

d = r * t

r1 * t + r2 * t = 912

Solution

3x    + 3*(x + 12) = 912          Remove the brackets

3x +  3x + 36 = 912              Combine like terms

6x + 36 =   912                     Subtract 36 from both sides

      -36      -36

6x       =      876                   Divide both sides by 6  

6x/6   =       876/6

x =               146 km/h

Answer

Slow train = 146 km/hr

Fast train = 146 + 12 = 158 km/hr