Brain Teasers
Family Crossing River
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 mins
(F)Father - 8 mins
(M)Mother - 6 mins
(S)Sister - 3 mins
(B)Brother - 1 min
Can you help the family get across?
(G)Grandpa - 12 mins
(F)Father - 8 mins
(M)Mother - 6 mins
(S)Sister - 3 mins
(B)Brother - 1 min
Can you help the family get across?
Hint
Look at its category.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!
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Comments
made the first one !!!!!!!!!1 yeaaaah! good teaser love it lol
too easy
Come on that was just too easy!
really good i almost got it
Wrong.
You could have mentioned that the two people row together... that would take even less than 7 minutes.
You could have mentioned that the two people row together... that would take even less than 7 minutes.
Is this really a trick? I thought that there was an unmentioned bridge or something, lol. :p
i thought it was like bro goes w/t grandma sis goes with dad and mom goes by herself then it would take like 10 min. or sumthin and no one would have to go back also you could have mentioned that a family member could go twice
I don't think this is a trick as much as it is a logic puzzle....
I thought that they could just grab onto the sides of the boat while the brother rows
I thought that they could just grab onto the sides of the boat while the brother rows
Ha. Nice.
I figured such but wasn't sure if only one person rows at a time or what
My answer was "no"
well, the hint said 'how do YOU help them', so you could push them one at a time across.
What, they can't row across in the dark?
Grr.. tricked again!
I like it I just don't understand how this falls into the "trick catagory".
Loved it!!!!!!!!!
my math teacher gave our class a problem similar to this, but we actually had to solve it. I thought the answer (to the teaser) was they get another lamp or another boat... great teaser anyway! :
wait if each of them can row the boat at a certain speed the grandpa could row the mother across and that would take 12 mins, the son could go alone which is a total of 13 minutes and the father could row the sister across in another 8 minutes for a total of 21 minutes they would still have 7 minutes of light left! i have helped the family get across its just not the fastest way to do it. if thats what you wanted you should state that you want the fastest route.
My answer was no, because I'm not there to help.
Yeah I thought it had something to do with "What could YOU do to help?" and the answer is Nothing.
Can't they swim?
why do they need a light to get across???
Cindzey: It's dark.
Nice one, but a bit easy for me Loved it still though
Nice one, but a bit easy for me Loved it still though
But it makes me think though, Brother must be seriously tired by then
But it makes me think though, Brother must be seriously tired by then
How is that a trick? That seems to be just arithmetic... Very simple arithmetic... I thought the trick was that, in answer to the question "Can you help them get across?" the reply was "no"
I thought the answer was: No, I cannot help them cross the river because I'm not there lol
Got it right! Great teaser; in my faves.
I agree with Musik
Wouldn't the boy get tired after a while though?
Wouldn't the boy get tired after a while though?
my answer was lamps dont burn way off
If you accept the premise that the dilemma is based on the fact that they need light, then why don't they just wait until the morning? After all, this puzzle is in the "Trick" category.
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