Saturday

April 19, 2014

April 19, 2014

Posted by **John** on Monday, December 5, 2011 at 2:18pm.

- math -
**MathMate**, Monday, December 5, 2011 at 3:46pmUsing algebra:

let x=speed of slower train

then x+25 = speed of faster train

After two hours, total distance travelled:

2(x + x+25) = 162 miles

divide by two to get

2x+25 = 81

2x=81-25=56

x=28 mph (slower train, it'd better be half price!)

faster train = 28+25 = 53 mph

Check: (28+53)*2=162 :)

By mental calculations, no pen, paper nor calculator:

Reasoning:

Over two hours, the faster train travelled 50 miles more than the slower. So if both travelled at the slower speed, they would have travelled a total of 162-50=112miles in two hours. Each (of the slower) will have a speed of 112/4=28 mph. The faster one, of course, travels at 28+25=53 mph.

**Related Questions**

math - Two trains depart at the same time from the same station and travel in ...

Pre-Calculus-Trig - Two trains depart simultaneously from the same station. The ...

math - 2 trains leave the same train station at the same time, one train travels...

math - Supppose two trains leave Holbrook, Arizona, at the same time, traveling ...

Physics - Two trains travel on the same railway in opposite direction. The ...

Physics - position time graph - The graph shows position as a function of time ...

trig - two trains leave Kansas City at the same time. Train A is traveling due ...

Math - Two trains leave a train station at the same time. One travels east at 11...

math - Two trains leave a train station at the same time. One travels east at 10...

Physics - As two trains move along a track, their conductors suddenly notice ...