A monkey climbs 30 ft at the beginning of each hour and rests for a while when he slips back 20 ft before he again starts climbing in the beginning of next hour. if he begins his ascent at 8 am at what time will he first touch a flag 120 ft from ground

A. 4 pm

B. 5 pm

C. 6 pm

D. None of these

Answer: Option B

Solution(By Examveda Team)

Monkey climbs 30 ft at the beginning of the hour and slips down 20 ft.
It means he climbs, 30 - 20 = 10 ft. per hour.
So, He will climb 90 ft. in 90/10 = 9 hours. And
In the beginning of 10th hour he will climb 30 ft and he will reach to the top so there will be no slips.
Thus, total time taken = 9 hours.
So, he will touch flag,
= 8 AM + 9 = 5 PM.