Traffic on NH4, the Chennai Banglore highway moves at a constant speed of 90 kms per hour in both directions. A Banglore bound driver passes 20 Chennai bound vehicles in a 2 minute interval. Assume that the vehicles in the Chennai bound lane are equally spaced. Which of the following answers is closest to the number of Chennai bound vehicles in a 90 kms stretch of the highway? [DCRU]
A. 225
B. 300
C. 600
D. 150

Answer is 300 bcz traffic is moving from both sided actuly driver watching 20 vehicle per 2 min then in one direction driver will see 10 vehicle 60/2*10=300 ans.
11 years agoHelpfull: Yes(9) No(4)
ans-600
in 2min- 20 vehichle
in 1min-10 vehichle
n in 60 min-600 vehichle
11 years agoHelpfull: Yes(6) No(7)
Relative speed of the driver=(90+90)=180km/hr
he moves 90km=1/2hr=30mins
in 2 min=20 vehicle
1 min=20/2 vehicle
30 min=30*20/2=300 vehicles.
11 years agoHelpfull: Yes(4) No(2)
relative speed of driver= 180kmph =300m/min 600 meter in every 2 mins.
now, in 2 mins the driver passes 20 vehicles, on a stretch of 0.6km
so in a 90km stretch, the no of vehicles= 20*90/0.6=300 vehicles.
10 years agoHelpfull: Yes(2) No(2)
600 km is the ans
11 years agoHelpfull: Yes(1) No(5)
speed = distance/time
as vehicles are moving from both the sides so relative speed is 180km/hr
let distance between two vehicles on one side be x
substituting the values in above formula we ger
180 = 20x/(2/60), so we get x=0.3km
let n be the no. of vehicles on road (on one side)
so 0.3n = 90, and so n = 300
so total vehicles on both sides will be 2n = 2 x 300 = 600 (answer)
7 years agoHelpfull: Yes(0) No(0)

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