# Instructing People to use minnimum time for a task? [duplicate]

There are 5 persons standing on a side of tunnel.

A, B, C, D, E


Each takes 10, 30, 15, 20, 29 minutes to cross tunnel respectively.

You are giving them instructions to cross.

Problem is at a time 2 person can cross tunnel with flash light.

After crossing one person should come back with flash light because its only one.

How you will manage them so that in a minimum time they can cross tunnel?