A monkey climbs 30 feet at the beginning of each hour and rests for a while when he slips back 20 feet before he again starts climbing in the beginning of the next hour. If he begins his ascent at 8.00 a.m., at what time will he first touch a flag at 120 feet from the ground?

A. 4 p.m.
B. 5 p.m.
C. 6 p.m.
D. None of these

• C. 6 p.m.
  
  A monkey climbs 30 feet at the beginning of each hour and rests for a while when he slips back 20 feet before he again starts climbing in the beginning of the next hour.
  
  It means monkey climbs effectively 10 ft in 1 hr.
  
  so it climbs 90 ft in 9 hrs .
  balance 30 ft is covered in 10th hr.
  
  So total it will take 10 hrs.
  
  Monkey will touch 120 ft flag at 8+10 = 1800 hrs or 6 PM.
• 13 years agoHelpfull: Yes(30) No(1)
• Right answer is missing. 19 hours in total it take to reach top. From 8am, 19 hours means 4AM. which is not there in the given options
  
  
• 13 years agoHelpfull: Yes(2) No(12)
• totally the monkey reach the distance in 10feets in 2hrs
  so10feets=2hrs
  9*10 feets=9*2hrs
  90feets=18hrs
  the remaining 30feets climb in 1hr.
  sothe monkey 120feets in 19hrs
  ansis 4p.m
• 13 years agoHelpfull: Yes(1) No(9)