PLZ HELP ASAP!!!!!!!,

Boris is playing on the mall escalators. One escalator goes up, one goes down, and one is out of service; otherwise, they're all identical. The up and down escalators go at the same speed. You can assume that Boris always runs at the same speed.

Boris can run up the up escalator in 6 seconds. He can run up the down escalator in 30 seconds. How long does it take him to run up the out-of-service escalator? Explain your answer

The answer to your question is 10 seconds. I know this because:

distance divided by speed=time
let t=time
t=2*6(30/36)=10
t=10
So, it took Boris a total of 10 seconds to run up the out of service elevator.

Hope this helps!

Answer Link

nuuk nuuk · Answer 2 · 2019-09-04T06:57:59+02:00

Answer:10 sec

Step-by-step explanation:

Given

Boris can run up the escalator in 6 sec

Also he can run up the down escalator in 30 sec

i.e. He travel same distance either ways

Let the distance be x and v be the speed of boris and [tex]v_0[/tex] be the speed of escalator.

[tex]x=6\times \left ( v+v_0\right )[/tex]----1

[tex]x=30\times\left ( v-v_0\right )[/tex]----2

Equating 1 and 2

[tex]5\left ( v-v_0\right )=v+v_0[/tex]

[tex]5v-5v_0=v+v_0[/tex]

[tex]v_0=\frac{2}{3}v[/tex]

substituting in 1

[tex]x=6\times \left ( v+v\frac{2}{3}\right )[/tex]

[tex]x=6\times v\frac{5}{3}=10v[/tex]

Thus form above equation we can say that it requires 10 sec for Boris to climb up in out of service escalator.