Question

An elevator descends into a mine shaft at the rate of 13m/min. If the descend starts from 20 m above
the ground level, how long will it take to reach - 240 m?​

Answer 1

$- 240 + 20 \\ = - 220 \div 60 \\ 11.5min$

Answer 2

Answer:

given rate=13m/min height from ground

level=20m,depth of mine from ground

level=240m

total height=260/13=20 min