This Week's NPR Weekend Edition Sunday Puzzle

The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them will
let anyone else know how much he weighs. And no scale at the flying club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001

Pragmatic solution: tell them to stop being childish and just tell
me what they weigh, or else stay on the ground while I go flying
and have some fun.

Of course there are a number of mathematical solutions. Personally
I wouldn't trust my passengers to do arithmetic correctly if my life
depended on it!

John

"john smith" wrote in message
...
The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them will
let anyone else know how much he weighs. And no scale at the flying club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001

"John Harper" wrote:
Personally I wouldn't trust my passengers to do arithmetic
correctly if my life depended on it!

Any Angel Flight pilot could tell you horror stories.
--
Dan
C172RG at BFM
(remove pants to reply by email)

john smith wrote in news:vsw_b.21$OE4.9
@fe1.columbus.rr.com:

The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them
will
let anyone else know how much he weighs. And no scale at the flying
club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001


He simply cancels the flight because his aircraft cannot take all 4 up at
once. The odds of 3 people being asked to go up in a plane together when
all of them are concerned about being underweight are vanishingly small.
Barring that they could go in to the room one at a time and weight then
selves and write down the weight on a piece of paper and insert it into a
slot in a lock box so no one could see the results until all 3 papers are
in the box. The pilot adds up the numbers and has his total weight and
no one know which wieght goes to which person.

John

1. Have each passenger pick up an unknown weight (suitcase, etc.) and
weigh with it to get a gross weight.

2. After all three are weighed that way, add these gross figures to
get a max gross weight of the group.

3. Take the 'added' weight (suitcases, etc.) each carried to get
weighed and weigh the three to get the excess weight.

4. Subtract the extra weights total from the max gross total and the
figure you get is the total passenger weight that can be used to
figure W & B.

May be a easier way but this will work and no individual will give
away his weight.

Big John


On Mon, 23 Feb 2004 23:58:19 GMT, john smith wrote:

The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them will
let anyone else know how much he weighs. And no scale at the flying club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001

In fact the problem is poorly formulated. The lockbox is
clearly the answer if they don't mind writing their weight
down. Or Big John's solution is quite neat. Or you could
have each passenger divide their weight into n unequal
parts and write each part down separately, giving you
3n pieces of paper which you then sum. No doubt you
could figure out how to use the Chinese Remainder Theorem
if you wanted to...

Or you could fly a 182 with half tanks - if they'll fit in
the plane, you'll be OK.

John

"John Theune" wrote in message
1...
john smith wrote in news:vsw_b.21$OE4.9
@fe1.columbus.rr.com:

The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them
will
let anyone else know how much he weighs. And no scale at the flying
club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001


He simply cancels the flight because his aircraft cannot take all 4 up at
once. The odds of 3 people being asked to go up in a plane together when
all of them are concerned about being underweight are vanishingly small.
Barring that they could go in to the room one at a time and weight then
selves and write down the weight on a piece of paper and insert it into a
slot in a lock box so no one could see the results until all 3 papers are
in the box. The pilot adds up the numbers and has his total weight and
no one know which wieght goes to which person.

stand next to them and make an "educated guess".. guess high.. and if the
numbers don't work out.. tell them they can't fly until they prove they are
below a set weight...

ever want to be the weight guesser at the local carny?

BT

"john smith" wrote in message
...
The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them will
let anyone else know how much he weighs. And no scale at the flying club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001

john smith opined

The Current Challenge (given February 22, 2004):

A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them will
let anyone else know how much he weighs. And no scale at the flying club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?

E-mail your answer to , or send a post card to:

PUZZLE
Weekend Edition Sunday
National Public Radio
635 Massachusetts Ave., NW
Washington, DC 20001


This one has beeen aroound before. What you do is whisper a random number to
person 1. He adds his weight to that number and whispers the result to person
2. He and person 3 dothe same. Person 3 tells the pilot the result of his
calculation. The pilot then subtracts the original random number and comes out
with the total of the passenger's weights.


-ash
Cthulhu for President!
Why vote for a lesser evil?

What you do is whisper a random number to
person 1. He adds his weight to that number and whispers the result to person
2. He and person 3 dothe same. Person 3 tells the pilot the result of his
calculation. The pilot then subtracts the original random number and comes out
with the total of the passenger's weights.


This works as long as all passengers are good at math, and there are no
telephone errors.

The likelyhood of this is not something I want to contemplate.

Jose

--
(for Email, make the obvious changes in my address)

Ash Wyllie wrote:
A private pilot has a four-seat plane, and he's offered to take three
friends up for a flight. To do his load and fuel calculations the pilot
needs to know the combined weight of his three passengers. Now, the
three passengers are sensitive about their weight, and none of them will
let anyone else know how much he weighs. And no scale at the flying club
is big enough to weigh more than one person at a time. How does the
pilot quickly get the accurate combined weight of the three passengers?


This one has beeen aroound before. What you do is whisper a random number to
person 1. He adds his weight to that number and whispers the result to person
2. He and person 3 dothe same. Person 3 tells the pilot the result of his
calculation. The pilot then subtracts the original random number and comes out
with the total of the passenger's weights.

I like that!
Simple and elegant.