Merry Christmas from The German Mathematical Society

[Herr Tubthumper]

Christmas in Germany is such a lovely time and every year the fun-loving German Mathematical Society plays its part and runs a Christmas puzzle. When you're out of things to say to the family try this.

Waldemar the Elf has a job to do: he must collect all the Christmas wish lists from children who live in the Sahara Desert. Starting in Timbuktu, he is able to complete the round trip and return to Timbuktu in six days. But he is an elf, which means he is very small. An elf can only carry a maximum of four days’ worth of elf food. What is the minimum number of elves Waldemar needs to bring with him to complete the trip?

Clarifications: Waldemar can only travel with other elves. Every elf on the trip must eat a day’s worth of elf food every day. Elf food is not available to buy during the trip, but elves can give each other food that they have brought with them. No elf is allowed to leave Timbuktu twice, nor be left stranded in the desert with no food.

 

[AmexRuislip]

two elves?

 

[Algernon]

elf elves ?

 

[happypig]

It's an elf version of Operation Black Buck

 

[Colonel Angus]

It's easy. Twenty two elves.

I've got to talk to my relatives again now.

Do the Germans have any more puzzles to solve before Queeny tells us what a bad year it's been for celebrities and a pretty good year for The Albion?

 

[Perkino]

This doesn't make any sense. If they cannot be left in the dessert then they must take 6 days worth of food! Which they cannot carry, having extra elves to carry your food means they either don't eat or die in the dessert

 

[Pogue Mahone]

This doesn't make any sense. If they cannot be left in the dessert then they must take 6 days worth of food! Which they cannot carry, having extra elves to carry your food means they either don't eat or die in the dessert

I don't think puddings are involved.

 

[Postman Pat]

This doesn't make any sense. If they cannot be left in the dessert then they must take 6 days worth of food! Which they cannot carry, having extra elves to carry your food means they either don't eat or die in the dessert

They can turn back when no longer needed

Day 0
Elf A,B,C - 4 days food

Day 1
Elf C gives 1 day food to Elf A and heads back
Elf A 4, elf B 3, elf c 2

Day 2
Elf B gives elf A one day food and heads home
Elf A 4 days, Elf b 2 days, Elf c home

Day 3
Elf A 3 days and 3 away, Elf b 1 day and 1 from home

Day 4
Elf B home
Elf A 2 days and 2 away

Elf A arrives on day 6

 

[The red pepper kid]

if Germany is that good--- stay there

 

[Postman Pat]

Sorry got that a little bit wrong, elf c gives a+b food on day 1 so elf b has 4 too so can make it back.

 

[SUA Seagull]

The answer is zero elves. The task would have been abandoned on the grounds of Elf and Safety.

 

[GT49er]

Seven.

W. has one companion all the way (1). They are accompanied for two days by four others (5). Then the four elves give one days worth each to W. and companion - W. and companion then go off with four days' supplies to get them through days 3, 4, 5, and 6. The other four elves use their last day's supply to trek back to the first stopping point, where they will be met by two others (total assistant elves now up to 7) who have travelled one day with four days' food. These two will give up two of their three remaining ones to the four returners to enable them to get back, and use their last remaining one to get back themselves.

 

[Herr Tubthumper]

if Germany is that good--- stay there

Merry Xmas to you as well....you grumpy ****.

 

[The Antikythera Mechanism]

One additional elf. 8 days food between the two of them. Kill recruited elf and steal his food. job done.

 

[Winker]

If there are any children living in the Sahara desert then they are probably muslims with no concept of Christmas, elves or food. This is a question of cultural imperialism with which I do not wish to take part. Anyway, the elves were beheaded.

 

[Norman Potting]

Clearly a job for the National Elf Service,

 

[Hampster Gull]

If one can travel on its own in the orher direction then i make it 4. If not then i make it 6. Where do i collect my elf prize HT?

 

[Eeyore]

Four: Waldemar leaves with three elves and four days food each. At the end of the first day, two return having eaten one day’s supply and keeping one for the return journey. Therefore between them they hand over four days food -two each for Waldemar and his accomplice. So for the remaining five days they have two days food plus the three they already have in stock.

 

[Bry Nylon]

Is the answer, no one gives a shit because they are Elves. And German?

 

[GT49er]

Edit.