An elevator named L in "63 Building" in Seoul is notorious for its low speed. It takes 3 seconds for L just to move one floor. It takes another 20 seconds for it to have its door open and close automatically.
What is even more frustrating, is that the elevator travels only to odd-numbered floors, and the doors will automatically open and close at all odd numbered floors.
How long will it take (in seconds) for L leaving the 1st floor "just to arrive" at the 35th floor?
Note:
Do not include the time taken for the doors to open / close at the 1st or 35th floor.
To calculate the time it takes for elevator L to travel from the 1st floor to the 35th floor, we need to consider two components: the time it takes to move between each floor and the number of floors between the 1st and 35th floors.
First, let's calculate the time it takes for L to move between each floor. We are given that it takes 3 seconds for L to move one floor. Since the elevator only travels to odd-numbered floors, we can divide the total number of floors that L can travel by 2. This gives us:
(35 floors) / 2 = 17.5 floors
However, since L can only travel to odd-numbered floors, we round this number up to the nearest whole number, which is 18 floors.
Next, let's calculate the time it takes for L to travel these 18 floors. Each floor takes 3 seconds to move, so the total time for the 18 floors would be:
18 floors * 3 seconds/floor = 54 seconds
Therefore, it would take L 54 seconds to travel from the 1st floor to the 35th floor, without including the time taken for the doors to open and close at the 1st or 35th floor.