Question

A man is climbing a pole 100 feet high. Each minute he climbs up 15 feet but slips down 10 feet in the next minute. How many minutes will he take to reach the top of the pole?

• A. $44$
• B. $38$
• C. $35$
• D. $34$

Answer 1

Answer: (C)

$35$

Given that:

A man is climbing a pole $100ft$ high.

Each minute he climbs $15ft$ but slips $10ft$ the next minute.

To find out:

Minutes he will take to reach the top of the pole.

The man climbs $15ft$ in a minute and then slips down $10ft$ in the next minute.

Hence, the distance he is able to climb in $2$ minutes $=15-10ft$

$=5ft$

Hence, the climbing speed of the man is $\frac{5}{2}ft/minute$

We know that, $\text{Speed}=\frac{\text{Distance}}{\text{Time}}$

Hence, $\text{Time}=\frac{\text{Distance}}{\text{Speed}}$

Now, the time he will take to climb the first $85ft=\frac{85}{\frac{5}{2}}$

$=85\times \frac{2}{5}$

$=34minutes$

After climbing $85ft$ in $34minutes$, the man will climb the remaining $15ft$ in one minute, to reach the top of the pole.

Hence, the total time taken to climb the pole $=34+1$

$=35minutes$

Hence, the man will take $35minutes$ to reach the top of the pole.