Question

Abdul, while driving to school, computes the average speed for his trip to be 20 km/hr. On his return trip along the same route, there is less traffic and the average speed is 40km/hr. What is the average sped for Abdul's trip?

Answer 1

Let d = distance from home to school.
Time to drive to school = d/20 hours.
Time for return trip = d/40
Total time for round trip = d/20 + d/40 = (3*d)/40
Total distance traveled = 2 * d
Average speed =
\[\frac{2d \times 40}{3d}=\frac{80}{3}km/hr\]

Answer 2

@kropot72 Why my formula isn't used?
Please tell:)

Answer 3

Thankyou thankyou thankyou..!! @maheshmeghwal9 !! ^_^
Thankyou sooo much :*

Answer 4

but thanku for wt?
@kropot72 gave the right answer:)

Answer 5

@maheshmeghwal9 Your method is incorrect. Check my workings and find out the reason.

Answer 6

k:) i gt it
@jahanvi I have done wrong.

Answer 7

My formula is use when initial & final velocity is given & acceleration is constant:)

Answer 8

used*

Answer 9

So initial velocity=u
final velocity =v
So;
\[V_{av.}=\frac{u+v}{2}.\]

Answer 10

but in ur question the trip is different
So @kropot72 is 100% right:)

Answer 11

@kropot72 gave answer\[\frac{80}{3}km/hr=26.67km/hr.\]which is correct.
So don't confuse both fraction & decimal are same^