A boy is running at a speed of p km/h to cover a distance of 1 km. But due to slippery ground his speed is reduced by q km/h. If he takes r hours to cover the distance, then which of the following equations is true?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(\frac{1}{r}=p-q\)
Time is distance divided by speed. A reduction of q km/h leaves the boy running at \(p-q\) km/h over the 1 km.
\(r=\frac{1}{p-q}\)
Taking the reciprocal of both sides: \(\frac{1}{r}=p-q\)