A monkey climbs 30 feet at the beginning of each hour and rests for a while when he slips back 20 ...
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?
Answer/Solution
6 p.m.
Steps/Work
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.
ANSWER:C
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.
ANSWER:C