a monkey ascends a greased pole at 21 m high. In the first minute he ascends 5 m and in the next minute he descends 3 m. If he continues this process, in how many minutes will he reach the top?
Answers
Step-by-step explanation:
Monkey ascends 2 m in first minute and slips 1 m in next minute.
It means he ascends 2−1=1 m in every two minutes.
Take 2 minutes =1 unit of time.
It will take 12 unit of time to climb 12 m of the pole.
In next 1 minute =12 unit +1=24+1=25 minutes.
Given: Height of the pole = 21 m
In the first minute the monkey ascends 5 m.
in the next minute the monkey descends 3 m.
To find: Time taken to reach the top
Solution: In the first minute the monkey ascends 5 m and in the next minute he descends 3 m.
Hence, the net height ascended in 2 minutes = (5 - 3) m = 2 m.
Therefore, the monkey actually ascends 1 m height every 1 minute.
So to ascend a greased pole at 21 m high, the monkey will take 21 minutes.
Answer: He will take 21 minutes to reach the top.