Question

The distance between two stations is 340 km. Two trains start simultaneously these stations on parallel tracks to cross each other. The speed of one of then greater than that of the other by 5 km/hr. If the distance between the two trains at hours of their start is 30 km, find the speed of each train

Easiest solution with best explanation​

Answer 1

Answer:distance(d)=rate(r) times time(t) or d=rt;t=d/r and r=d/t

Let r=rate (speed) of the first train

Then r+5=rate of the other

Distance first train travels in 2 hours =r*2 or 2r

Distance other train travels in 2 hours=(r+5)*2 or 2(r+5)

Now we know that the distance the first train travels (2r) plus the distance the other train travels (2(r+5)) equals 340-30 or 310 mi. So our equation to solve is:

2r+2(r+5)=310 mi get rid of parens

2r+2r+10=310 subtract 10 from both sides

2r+2r+10-10=310-10 collect like terms

4r=300 divide both sides by 4

r=75 mph---------------------------speed of first train

r+5=75+5= 80 mph---------------------speed of other train

CK

75*2+80*2=310

150+160=310

310=310

Step-by-step explanation: