Question 6
One day, Robert went to a library 1600 meters away from home to meet with his
classmates at 13 : 20. Robert leaves home at 13 : 00, walking at a constant speed
of 80 meters per minute. At exactly 13 : 05, Robert's mother noticed that he left
his wallet at home, so she chased him walking at a speed of 120 meters per
minute. Robert only realized he left his wallet at home at 13 : 10, so he walked
back casually at a speed of 80 meters per minute. Robert and his mother met
halfway through. After taking his wallet, he again walked back towards the
library at a speed of 80 meters per minute. If we ignore the time Robert took to
get the wallet from his mother, how much time, in minutes, did he waste?
classmates at 13 : 20. Robert leaves home at 13 : 00, walking at a constant speed
of 80 meters per minute. At exactly 13 : 05, Robert's mother noticed that he left
his wallet at home, so she chased him walking at a speed of 120 meters per
minute. Robert only realized he left his wallet at home at 13 : 10, so he walked
back casually at a speed of 80 meters per minute. Robert and his mother met
halfway through. After taking his wallet, he again walked back towards the
library at a speed of 80 meters per minute. If we ignore the time Robert took to
get the wallet from his mother, how much time, in minutes, did he waste?