|
Question 505180: If it takes you 30 seconds to reach the top of an escalator by just standing on it,and if it takes you 20 seconds to walk up the stairs.How much time it will take you to reach the top of the escalator by walking on it with the same rate you walked up the stairs.
Answer by ptaylor(2198)   (Show Source):
You can put this solution on YOUR website! If you ride the escalator, you travel 1/30th the distance to the top per sec
If you walk up the stairs you travel 1/20th the distance to the top per sec.
If you do both then you travel 1/30 + 1/20=1/12 the distance to the top per sec.
Sooooo, doing both it takes 12 seconds to reach the top.
another way:
Let x=time it takes to both ride the escalator and walk at the same time
Then (1/12)x=1( complete distance to top, that is)
x=12 sec
Hope this helps---ptaylor
|
|
|
| |
