A truck covers a distance of 480 km at a certain speed. If the speed is decreased by 8 km/h, it would have taken 2 hours more to cover the same distance. 50% of its original speed (in km/h) is:
Answer & explanation
Correct answer: option 4
Let initial speed = S km/h
So , New Speed = ( S - 8) km/h
We know ,
Time = \(\frac{Distance}{Speed}\)
According to question ,
\(\frac{480}{S - 8 }\) - \(\frac{480}{S}\) = 2 hours
\(\frac{240× 8 }{S ( S - 8)}\) = 1
1920 = S(S-8)
S = 48 km/h
50% of S = \(\frac{1}{2}\) × 48 = 24 km/h
So , 50% of initial speed is 24 km/h