Manish walks on the mountain up to a certain distance and rides back taking a total time of 27 minutes. Manish could walk both ways in 45 minutes. How long would it take Manish to ride both ways.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 9 min
Let walking one way take \(w\) minutes and riding one way take \(r\) minutes. Walking both ways gives the walking time, and the mixed trip then gives the riding time for one way.
Walk one way and ride back: \(w+r=27\) (1)
Walk both ways: \(2w=45\), so \(w=22.5\) (2)
Putting (2) in (1): \(r=27-22.5=4.5\)
Riding both ways: \(2r=9\) minutes
Shortcut:
Doubling the mixed trip gives two walks and two rides: \(2\times27=54\) minutes
Taking away the two walks leaves the two rides: \(54-45=9\) minutes