A person is rowing a boat in the downstream 20 km in 30 minutes and sp

1.	A person is rowing a boat in the downstream 20 km in 30 minutes and speed of the current is 10 km/hr. Find the speed of a boat.1. 30 km/hr2. 25 km/hr3. 35 km/hr4. 22.5 km/hr
Answer» Correct Answer - Option 1 : 30 km/hr Given: Distance travelled in the downstream = 20 km And the time is taken to travel the distance in the downstream = 30 minutes. Speed of the current = 10 km/hr Formula used: If x is the speed of the boat and y is the speed of the current, then Downstream speed = x + y 1 hour = 60 minutes Speed = distance/time Calculation: Let the speed of a boat be x km/hr and speed of the current be y km/hr Downstream speed = (20)/(30/60) ⇒ 20 × 60/30 ⇒ 40 km/hr Downstream speed = x + y ⇒ 40 = x + y ⇒ 40 = x + 10 ⇒ x = 40 - 10 ⇒ x = 30 km/hr ∴ The speed of a boat is 30 km/hr

A person is rowing a boat in the downstream 20 km in 30 minutes and speed of the current is 10 km/hr. Find the speed of a boat.1. 30 km/hr2. 25 km/hr3. 35 km/hr4. 22.5 km/hr

Answer» Correct Answer - Option 1 : 30 km/hr

Given:

Distance travelled in the downstream = 20 km

And the time is taken to travel the distance in the downstream = 30 minutes.

Speed of the current = 10 km/hr

Formula used:

If x is the speed of the boat and y is the speed of the current, then

Downstream speed = x + y

1 hour = 60 minutes

Speed = distance/time

Calculation:

Let the speed of a boat be x km/hr and speed of the current be y km/hr

Downstream speed = (20)/(30/60)

⇒ 20 × 60/30

⇒ 40 km/hr

Downstream speed = x + y

⇒ 40 = x + y

⇒ 40 = x + 10

⇒ x = 40 - 10

⇒ x = 30 km/hr

∴ The speed of a boat is 30 km/hr

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