There are 4 women having walking speed as 1min, 2min, 4min, 5min. If one or two women can cross bridge at a time with flashlight, then what is min. time required for 4 women to cross bridge without using flashlight?

• 12 min
  
  Fist 1 min and 2 min women cross in 2 min..... total 2 min
  then 1 min woman comes back in 1 min......... total 3 min
  Then 4 min and 4 min move in 5 min........ total 8 min
  2min woman comes back in 2 min ...................10 min.
  1 min and 2 min women cross in 2 min..... total 12 min
  
• 13 years agoHelpfull: Yes(2) No(1)