It is a dark night and there is a family of 5 that needs to use a boat to cross a river. The only light available is a lamp which can only burn for 28 minutes. Up to two members can cross each time; otherwise, the boat will sink. Different members take different amounts of time to row the boat. The time taken for each member is as shown:
(G) Grandpa – 12 min
(F) Father – 8 min
(M) Mother – 6 min
(S) Sister – 3 min
(B) Brother – 1 min
Can you help the family get across?
Answer
If two people cross the river, the faster one rows the boat, and the time they take is the pace of the faster one.
Therefore, the brother goes with each other person each time, and comes back. It only takes 7 minutes!
