If a boat goes upstream at a speed of 36 km/h and comes back the same

1.	If a boat goes upstream at a speed of 36 km/h and comes back the same distance at 60 km/h. What is the average speed (in km/h) for the total journey?1. 542. 423. 454. 50
Answer» Correct Answer - Option 3 : 45 Given: A boat goes upstream at a speed of 36 km/h and comes back the same distance at 60 km/h. Formula used: average speed = total distance travelled/total time taken Calculations: let the distance travelled while going upstream be x km. distance for downstream is also the same. so the time taken while going upstream = x/36 and the time taken while coming downstream = x/60 thus average speed = \(\frac{2x}{\frac{x}{36}\ +\ \frac{x}{60}}\) ⇒ 2x × (180/8x) ⇒ 45 km/h ∴ The average speed in entire journey is 45 km/h

If a boat goes upstream at a speed of 36 km/h and comes back the same distance at 60 km/h. What is the average speed (in km/h) for the total journey?1. 542. 423. 454. 50

Answer» Correct Answer - Option 3 : 45

Given:

A boat goes upstream at a speed of 36 km/h and comes back the same distance at 60 km/h.

Formula used:

average speed = total distance travelled/total time taken

Calculations:

let the distance travelled while going upstream be x km.

distance for downstream is also the same.

so the time taken while going upstream = x/36

and the time taken while coming downstream = x/60

thus average speed = \(\frac{2x}{\frac{x}{36}\ +\ \frac{x}{60}}\)

⇒ 2x × (180/8x)

⇒ 45 km/h

∴ The average speed in entire journey is 45 km/h

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