Question

Four friends A, B, C, D need to cross a bridge..

A maximum of 2 people can cross at a time..
It is night and they have just 1 lamp.

People that cross the bridge must carry the lamp to see the way..
A pair must walk together at the speed of slower person…

Speeds of
A: 1 minute to cross bridge
B: 2 minutes to cross bridge
C: 8 minutes to cross bridge
D: 11 minutes to cross bridge

Now question is… “what is the total minimum time required by all 4 friends to cross the bridge….?​

Answer 1

Answer:

Here, A takes the shortest time to cross the bridge i.e. 1 min. And, D takes 10 min, C takes 7 min and B takes 2 min to cross the bridge.

So 4 friends can cross the bridge in minimum time in the following ways.

 A + B crossing and A returning : (2 + 1) min 2. A + C crossing and A returning : (7 + 1) min 3.

A + D crossing and A returning : (10 + 1) min 4.

A crossing the bridge for the last time: 1 min.

Hence, total minimum time = 3 + 8 + 11 + 1 = 23 min.

Answer 2

Answer:

srrry i dont know this andwer