Question

a bus travel a distance of 120 km with a speed of 40km/hr and return with a speed of 30 km. calculate the average speed for the entire journey​

Answer 1

Answer:

In first case:

S1 = 120Km

V1 = 40Km/h

T1 = 120/40 = 3hr.

In second case:

S2 = 120km  

V2 = 30km/h

T2 = 120/30 = 4hr

SO,

total time taken= 3+4=7hr

AND, Total distance covered = 120+120 = 240km

Average speed = total distance traveled (s) / total time taken (t)

SO, Average speed = Total distance covered/Total time taken = 240/7=34.28Km/hr.

Explanation:

HOPE IT HELPS U........................

Answer 2

Given :-

Distance travelled by the bus in 40 km/h = 120 km

Speed taken to return = 30 km/h

To Find :-

The average speed for the entire journey.

Solution :-

We know that,

• d = Distance
• s = Speed
• t = Time

Using the formula,

$\underline{\boxed{\sf Time \ taken=\dfrac{Distance}{Speed} }}$

CASE I:

Given,

Distance (d) = 120 km

Speed (s) = 40 km/h

Substituting their values,

t = 120/40

t = 3 hours

CASE II:

Given,

Distance (d) = 120 km

Speed (s) = 30 km/h

Substituting their values,

t = 120/30

t = 3 hours

According to the question,

Total time taken = t₁ + t₂

Substituting them,

Total time = 4 + 3

= 7 hours

Then, next

Total distance covered = d₁ + d₂

Substituting them,

Total distance = 120 + 120

= 240 km

Using the formula,

$\underline{\boxed{\sf Average \ speed=\dfrac{Total \ distance}{Total \ time} }}$

Given that,

Total distance (d) = 240 km

Total time (t) = 7 hours

Substituting their values,

s = 240/7

s = 34.28 km/h

Therefore, the average speed for the entire journey​ is 34.28 km/h.