Question

A racing car moving at a speed of $120km{h}^{-1}$ finishes the race in 4 minutes. The car registered second place, while the winner had finished 2 minutes before. What is the speed of the winning car?

• A. $300km{h}^{-1}$
• B. $240km{h}^{-1}$
• C. $200km{h}^{-1}$
• D. $160km{h}^{-1}$

Answer 1

The correct option is B $240km{h}^{-1}$

A racing car finishes the race in 4 minutes while moving at the speed of $120km{h}^{-1}$. So, the length of the track$=120\times \frac{4}{60}=8km$
The winning car takes 2 minutes to cover the same track.
The speed of the winning car is given by,
Speed$=8÷\frac{2}{60}=240km{h}^{-1}$