Topic - Escalators (Time, Speed & Distance)

Answer key available? - Yes

Source - Curated Content ]]>

Topic - Escalators (Time, Speed & Distance)

Answer key available? - Yes

Source - Curated Content ]]>

AP & HP concept can be used

Since the speeds are in AP, time taken will be in HP = 2 * 30 * 70/100 = 42

Method 2:

Let escalator moves "a" steps in case of Sam and "b" steps in case of john.

(Note : Escalator will move different no of steps in both the case as time taken will be different)

Let the number of steps required when escalator is stopped be "x".

30 + a = x --(1)

70 - b = x --(2)

30 + a = 70 - b --(3)

Now, Speed of both Sam and John is same.

So, If they take equal steps, then the escalator will also take equal step.

When Sam takes 30, Escalator takes "a" steps

=> Sam takes 210, Escalator takes 7a

When John takes 70, Escalator takes "b" steps

=> John takes 210, Escalator takes 3b

(Common Ratio : 210)

Hence, 7a = 3b --(4)

Solve(3) and (4), a = 12

Hence, x =42

[Credits : Akshay Kumar]

6 = 9n

n = 2/3

so steps= 8 + 2/3 * 375/10 = 8 + 25 = 33

so 33 * 3/2= 49.5 seconds

[credits - @swetabh_kumar] ]]>

a) What is the total number of steps in the escalator?

b) What is the difference in the number of steps that both of them had taken when they crossed each other? ]]>

Since both of them take the same time for the same distance, their effective speed is the same.

=> 5s - x = 3s + x

=> x = s

Speed of Ravi : Speed of escalator = 3s : s = 3 : 1

=> When Ravi takes 30 steps, the escalator takes 10 steps.

=> Total number of steps = 30 + 10 = 40 steps.

Both of them would have covered 20 steps when they crossed each other.

Ravi going up would have taken 15 steps, whereas the escalator would have taken 5 steps for him.

Rakesh coming down would have taken 25 steps, out of which the escalator would have nullified the movement of 5 steps for him.

Difference in the number of steps = 25 - 15 = 10

[credits : Biswanath Chakraborty] ]]>

Steps covered per sec = 3 + 2 = 5

when moving in stationary escalator

steps covered per sec = 2

Let the total steps = X

X/2 - X / 5 = 3

X = 10

[credits: Abhishek Dangayach] ]]>

12e = 8

e = 2/3

26 + 20 = 46 ]]>

(a) 100

(b) 120

(c) 150

(d) 160 ]]>

so let his earlier speed be 1 step/minute and speed of escalator be x.

So time taken to walk 10 steps is 10 mins

Case 1) 10 + 10x

Case 2) His speed increases by 5 times so new speed becomes 5 steps/ min and time taken is 5 mins

25 - 5x

10 + 10x = 25 - 5x

x = 1

total stairs = 20

[Credits : Shweta Arora] ]]>

e = 8

Total steps = 20 + 5 x 8 = 60 ]]>

Ramesh = 2

25 + 25e/3 = 20 + 10e

e = 3

Total steps : 20 + 10 x 3 = 50 ]]>

Speed of escalator = n steps/min up only.

In 30 secs,

Total steps upward = (x+n)/2 steps

In 90 secs downwards = (x-n)*3/2 steps

These two steps count should be equal.

x = 2n

Time taken= 45 secs

[credits: Rohit Kumar Pandey] ]]>

B = 2 steps/min and the speed of escalator = e

30 + 30e = 120 - 60e

90e = 90

e = 1step/min

Total steps = 30 + 30 x 1 = 60

[credits : Shivam Agrawal] ]]>

a) 30

b) 45

c) 60

d) 90

e) None of these ]]>

when both are moving up

S = (E+1)

T = 30

So D = 30 (E+1)

Now when man moves down on up moving escalator

S= (1-E)

T = 90

D= 30(E+1)

on solving E = 1/2 steps per sec

D= 45 ]]>

a) 80

b) 90

c) 120

d) 150 ]]>