A person covers a distance of 36 km in 5 hours. Part of the journey is covered on foot at 6 km/hr and the rest by cycle at 9 km/hr. What distance is covered on foot?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 18 km
The time on foot and the time on the cycle add up to 5 hours, and the two distances add up to 36 km.
Let the distance on foot be \(x\) km; by cycle it is \((36-x)\) km
\(\displaystyle \frac{x}{6}+\frac{36-x}{9}=5\)
Multiplying by 18: \(3x+2(36-x)=90\), so \(x+72=90\)
\(x=18\) km
The distance covered on foot is 18 km.