A fireman is on the middle step of a ladder. (There are the same number of steps above him as below him.) If he goes down 4 steps, then up 7 steps, and then down 13 steps, he will be on the first step above the ground. How many steps does the ladder have?

The ladder has 20 steps

Step-by-step explanation:

10 is the direct middle if you go down 4 that is 6, if you go back up 7 you get 13 and if you go back down 13 and you are on the first step 13-13 is 0, so the ladder has 20 steps.

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,