Mr X takes 30 seconds to go up by using moving up escalator and takes 120 seconds to come down

ans=48sec

Explanation
let x is speed of man
and y is speed of escalator
and d is the distance

d/(x+y)=30 and d/(x-y)=120
solving this we get 3x=5y, y=3x/5;
we have to fine that d/x=?
put y in d/(x+y)=30 ,we get d/x=48
10 years agoHelpfull: Yes(9) No(1)
answer is 80 sec
10 years agoHelpfull: Yes(5) No(6)
KUMAR AND SAURABH,, there is one kistake in ur solution : when the escalator and man go in opposite direction then there relative speed will be x+y/120; not x-y/30
9 years agoHelpfull: Yes(1) No(5)
75 .
because let the standstill time be t .
t - y = 30
t + y = 120
2*t = 150
t = 75
10 years agoHelpfull: Yes(0) No(12)
x+y==D/30.(d==distance)and x-y==D/120.2x==5D/120.x==D/48.y==D/30-D/48==D/80.as escaltor's speed should be smaller so ..80ans
10 years agoHelpfull: Yes(0) No(5)
let the total total distance cover = d
let the speed of Mr. X = X
let the speed of escalator = E

X + E = x / 30
X - E = x / 120
-X + E = - (x / 120)

2E = (x / 30 - x / 120)
2E = x / 30 * (3 / 4)
E = x / 80

time = 80 sec
10 years agoHelpfull: Yes(0) No(8)
suppose speed of man is S1 and speed of escalator is S2.
so according to question distance travelled
d=(S1+S2)30=(S1-S2)120 => S2=3S1/5

now if s2=0

d=S1*t
=> (s1+s2)30=s1*t
=> 30*8S1/3=s1*t
=> t=80 second
8 years agoHelpfull: Yes(0) No(3)

Mr. X takes 30 seconds to go up by using "moving up" escalator and takes 120 seconds to come down using "moving up" escalator. Find the tome to move up when the escalator is standstill.