Raghu notices that a boat of length 1000 m, when going downstream passes a Kashi Ghat along the Yamuna River in 150 seconds and while in return it passes the Kashi Ghat in 300 seconds. Find the length (in m) of the Kashi Ghat, if the speed of the current is 5 m/s.
Raghu notices that a boat of length 1000 m, when going downstream passes a Kashi Ghat along the Yamuna River in 150 seconds and while in return it passes the Kashi Ghat in 300 seconds. Find the length (in m) of the Kashi Ghat, if the speed of the current is 5 m/s.
1). 2000
2). 3000
3). 2100
4). 2200
1 answers
Let the length of Kashi Ghat be ‘x’ m and speed of boat be‘y’ m/s.
Distance cover by the boat = Length of the Ghat + length of the boat = x + 1000
Now notice that in downstream it takes 150 seconds while 300 seconds in upstream it means the speed of downstream is twice than speed upstream.
⇒ Downstream speed = 2 × Upstream speed
⇒ y + 5 = 2 × (y – 5)
⇒ y + 5 = 2y – 10
⇒ y = 15
In Downstream it takes 150 seconds,
⇒ 150 = (x + 1000) / (15 + 5)
⇒ 150 × 20 = x + 1000
⇒ 3000 = x + 1000
⇒ x = 2000
∴ Length of the Kashi Ghat is 2000 m.