There is a group of 4 people who have to cross a long and rickety bridge at night. They have only one torch (which is
required to cross the bridge) and the bridge can carry only 2 people at a time. The times taken by the 4 people to cross
the bridge are 1 minute, 3 minutes, 4 minutes and 7 minutes. (When two people are crossing together, the time taken is
equal to that of the slower one). What is the minimum time required, in minutes, for them all to cross?

• 1 and 2 go cross
  2 comes back
  7 and 10 go across
  1 comes back
  1 and 2 go across (done)
  
  Total time = 2 + 2 + 10 + 1 + 2 = 17 mins
  
• 11 years agoHelpfull: Yes(0) No(0)