The time taken by a ship to travel 1000 km upstream is 40 hours more than the time taken by it to travel the same distance in downstream. The speed of the ship in still water is 200% more than that of the speed of stream. Quantity I: How much time the ship will take to travel the same distance in upstream?  Quantity II: How much time the ship will take to travel 2000 km downstream if due to wind, the speed of stream was increased by 50%?

The time taken by a ship to travel 1000 km upstream is 40 hours more than the time taken by it to travel the same distance in downstream. The speed of the ship in still water is 200% more than that of the speed of stream. Quantity I: How much time the ship will take to travel the same distance in upstream?  Quantity II: How much time the ship will take to travel 2000 km downstream if due to wind, the speed of stream was increased by 50%? Correct Answer Quantity 1 > Quantity 2

Given:

Distance travelled = 1000 km

Time taken to travel upstream = 40 hours + time taken to travel downstream

Speed of wind = 50% more

Calculations:

Let the speed of the stream = X km per hour

⇒ The speed of the ship in still water = (100 + 200)% of X

⇒ 300% of X

⇒ 3 × X km per hour

According to the question,

⇒ (1000/(3X – X)) – (1000/(3X + X)) = 40

⇒ (1000/2X) – (1000/4X) = 40

⇒ 1000 × 2 = 8X × 40

⇒ X = 6.25 km/hr

Quantity I :

The required time = 1000/(3X – X)

⇒ 1000/2X

⇒ 1000/(2 × 6.25)

∴ required time = 80 hours

⇒ New speed of stream = 1.5x 

Quantity II :

W hen the speed of stream was increased by 50% then the new speed of the stream = 150% of x

⇒ New speed of stream = 1.5 × 6.25

⇒ New speed of stream = 9.375 km/hr

⇒ The speed of the ship in downstream = 3x + x = 4x, where x = new speed of stream 

⇒ 9.375 × 4 = 37.5 km/hr

⇒ The required time = 2000/37.5 ≈ 53 hours

Related Questions

Each of the question below consists of a question and three statements number I, II and III given below it. You have to decide whether the data provided in the statement are sufficient to answer the question. If the bus is travelling from Surat to Ahmadabad and a car is travelling from Ahmadabad to Surat, then what is the distance between Surat and Ahmadabad? I. The speed of a car is 40% less than the speed of bus. Bus started at 9 am and car started at 10 am and they meet at 3 pm of the same day. II. After travelling for 1 hour, because of traffic average speed of bus is decreased by 20% and covers distance between Surat to Ahmadabad in 11 hours. Original speed of car is 20% less than original speed of bus and before crossing bus it covered 200 km if starts 1 hour later than bus. After crossing car, bus covers remaining distance in 5 hours. III. Speed of bus is 10 km/hr more than the speed of car and before crossing car ratio of distances covered bus and car in same time was 5 : 4. Time taken by car to cover the distance between Ahmadabad and Surat is 2 hours 15 minutes more than time taken by bus to cover the same distance.