Walking at 6/7th of his usual speed, a man is 25 mins too late. His usual time is

a) 7.5 hrs b) 1.5 hrs c) 2.5 hrs d) 1.67 hrs

• Option C 2.5 hrs
  
  As the distance is same s*t=6/7s*(t+25)
  solving this we get t=150 sec
  150/60=2.5 hrs
  
• 12 years agoHelpfull: Yes(3) No(0)
• usual speed:s
  usual time:t
  new usual speed:6/7s
  new usual time:7/6t(as time s the reciprocal of speed)
  7/6t-t=12/60
  t/6=1/5
  t=6/5= 1 1/5
  wich is 1 hr 12 minutes
• 10 years agoHelpfull: Yes(0) No(0)