Two trains are 500 miles apart when they first enter a collision course. if, after two hours, the distance between them is 300 miles and one train goes 20 mph faster than the other, find the speed of the faster train.

60

Step-by-step explanation:

slow train = x

fast train = x + 20

First we get the amount of distance both trains have covered

500 - 300 = 200

Next we have to divide it by the number of hours it took

200 ÷ 2 = 100

Then we write our equation

x + x + 20 = 100

2x + 20 = 100

Subtract 20 from both sides

2x = 80

Divide 2 from both sides and your left with

x = 40

Next we write our expression for the faster train

x + 20

Since we found that x is 40, we plug it into the expression which is

now an equation and we get...

40 + 20 = 60

Answer = 60 mph

the answer is 13 cm

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.