A boy is running at a speed of p km/hr to cover a distance of 1 km. But, due to the slippery ground, his speed is reduced by q km/hr (p>q). If he takes r hours to cover the distance, then
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(\frac{1}{r}=p-q\)
The relation comes from speed \(=\frac{\text{distance}}{\text{time}}\), used with the speed he actually runs at.
Speed after the reduction \(=(p-q)\) km/hr
Distance \(=1\) km and time \(=r\) hours, so speed \(\displaystyle =\frac{1}{r}\)
Equating the two, \(\displaystyle \frac{1}{r}=p-q\)