A man travels by a car for 3 days. he traveled 10 hours each day. he drove on the first day at 45 km/hr, second day at 40 km/hr and third day at 20 km/hr. his average speed was :
Answers
=> avg speed = (45 + 40 + 20)/3
= 95/3km/h
Therefore the Average Speed of the car for 3 days is 35 kmph.
Given:
Time traveled by car on each of the 3 days = 10 hrs
Speed of car on the 1st day = S₁ = 45 kmph
Speed of car on the 2nd day = S₂ = 40 kmph
Speed of car on the 3rd day = S₃ = 20 kmph
To Find:
The Average Speed of the car
Solution:
This question on Average Speed can be solved as shown in the steps below.
Speed of car on the 1st day = S₁ = 45 kmph
Speed of car on the 2nd day = S₂ = 40 kmph
Speed of car on the 3rd day = S₃ = 20 kmph
Time traveled by car on each of the 3 days = T₁ = T₂ = T₃ = 10 hrs
⇒ Speed = ( Distance Travelled )/( Time Taken )
Distance travelled on the 1st day D₁ = S₁ × T₁ = 45 × 10 = 450 km
Distance travelled on the 2nd day D₂ = S₂ × T₂ = 40 × 10 = 400 km
Distance travelled on the 3rd day D₃ = S₃ × T₃ = 20 × 10 = 200 km
The mathematical formula for Average speed is given by,
⇒ Average Speed = ( Total Distance Travelled )/( Total Time Taken )
Total Distance Travelled = D₁ + D₂ + D₃ = 450 + 400 + 200 = 1050 km
Total Time taken = T₁ + T₂ + T₃ = 10 + 10 + 10 = 30 hr
⇒ Average Speed = 1050 / 30 = 35
Therefore the Average Speed of the car for 3 days is 35 kmph.
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