# A building is 'x' meters tall and has an elevator which goes  from the ground floor to the terrace of the building.  Currently, it is at the 4th floor which is at a height of 20 m from the ground. From there, it goes to the terrace and then goes back to the ground floor.  Which of the following expressions represents the TOTAL distance covered by the elevator, in metres?  A. (2x-4)  B. (2x-20)  c. (2x+20)  D. (2x-40)

Dear Student,

Given : A building is ' x ' meters tall and has an elevator which goes from the ground floor to the terrace of the building.

And

Currently, it is at the 4th  floor which is at a height of 20 m from the ground. From there, it goes to the terrace , So

Distance cover by lift from 4th  floor to terrace = ( x  - 20 ) meters

And then lift goes back to the ground floor. , So

Distance cover by lift from  terrace to ground floor = x   meters

Therefore,

Total distance covered by the elevator = x - 20 + x =   ( 2 x  - 20 ) meters

So,

Option ( B )                                                                                     ( Ans )