Family Crossing
21 Answers 
Challenge Your Friends
Tweet this
Today’s puzzler is from Borrow-A-Geek:
There are two sons and a dad, a row boat and a river to cross.
Each son weighs 75lbs
The dad weighs 150lbs
The row boat capacity is 150lbs
They all need to get accross the river, how can they do this with out ropes or any fancy tricks?
Get Puzzles Delivered:
Both sons row across, son 1 rows back.
Dad rows across alone, son 2 rows back.
Both sons row across.
Bob & Dave (the 2 sons) both jump into the boat and cross the river. Bob hops out on the opposite shore and cracks a beer while Dave rows the boat back. Dave hops out and Dad gets in and crosses alone. Dad gets out on the opposite shore and accepts the (mostly) empty beer from Bob who hops in and rows back across and picks up Dave (who has just finished his own beer) before making the final crossing. One more trip by Bob or Dave is needed to bring the beer cooler across, but that is not part of the puzzle so I am ignoring that…
Same answer as Dan I cant think of anything more efficient.
Alternative solution: They all get in the boat and sail in circles while the 2 sons frantically bail out the boat.
Nice one robwala.
Not sure if this is even needed, but I confirm and agree with Dan’s answer.
Swim.
Dad sits in the boat and rows while the two sons hang on to the back of the boat and kick like crazy. Nobody said there were any oars.
I am really thankful to this topic because it really gives great information *”-
step1:both sons cross
step2:one son returns
step3:father crosses
step4:the other son takes the boat back
step5:both sons cross
Step 1: Both son cross river
Step 2: 1 Stay there and 1 come back
Step 3: Father stay there and second son come back
Step 4: Both son cross the river
Two boys get in boat, dad in water, hanging on back of boat, kicking his feet to help propel the boat to the other side.
1)A son and B son(75lbs and 75lbs)will cross the river (total 150lbs)
2)A son came back and only father cross the river (total 150lbs)
3) B son waiting on the other side came back for his brother A son (total 75lbs)
4) Both A son and B son cross the river total weight (total 150lbs)
The two sons get in the boat, the father swims across, pushing the boat ahead of him.
Both Sons go first…
One returns…
One Son stays back…
Dad goes..
One son comes back to take his brother…
both of them row back to the other shore…
Happy Family!!
Son A and son B cross the river.
Son B crosses the river back to meet father.
Father crosses the river to meet son A.
Son A crosses the river back to meet son B.
Both son B and son A cross the river.
All three have left their mother behind!
Vanessa, your solution is correct, but if they all three have the same mother that would be quite disturbing.
first tow sons go and one leaves on the other side and the sons rows back,then the father alone goes to the other side and the son who is waiting there rows back and both the brothers come to the bank
1. The two sons cross from side A to side B
2. One of the sons return with the boat from side b to A.
3. The son remains in side A while the dad crosses from side A to B.
4. The remaining sons in side B returns with the boat from side B to A and leaves the dad in side B.
5. The two sons cross from side A to B.
OPTION B
Or they can all swim to the other side.
Here, “” in brackets represents river
1) Two sons row across river(15075,75)
2) One son brings boat back(150,7575)
3) Dad rows across river alone(75150,75)
4) One son from across river comes back to pickup second son(75,75150)
5) Both sons rows across river(no-on75,75,150)
Enjoy !!!
First and second kid cross with the boat
First kid returns with the boat
Father crosses with the boat
Second kid returns with the boat
First and second kid cross with the boat
The two sons take the boat across. One of them rows back. The father then goes across. The other son who remained on the other side rows back and gets his brother.