Math Is Fun Forum

rkonweb

Member

Registered: 2010-06-24

Posts: 1

its tof to answer ?

1+3+5+7+9+11+13+15+17+19=100
pick any five digit and by adding them total should be 50.
u can use one digit at once.....

thanks in advance

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: its tof to answer ?

Hi rkonweb;

Unless you do something other than just pick from {1,3,5,7,9,11,13,15,17,19} the problem has no solution. 5 odd numbers added together equal an odd number and 50 is not odd.

One answer I found is:

1 + 4 + 9 + 17 + 19 = 50 but it has a 4 which is not in {1,3,5,7,9,11,13,15,17,19}

There are others.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

aawood

Member

Registered: 2010-06-25

Posts: 2

Re: its tof to answer ?

As you say, adding any 5 odd numbers would make it impossible, but he mentioned any 5 digits rather than numbers. We can therefore use that to get 4 odd numbers using 5 digits from the sequence that add up to 50. One I found was 1 + 5 + 9 + 35.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: its tof to answer ?

H aawood;

Yes, there are other ways if we begin to interpret the question. How do we know that is what he wants. So far, 3 different answers, all of them correct. Maybe, he wants something else.

Based on his first statement:

1+3+5+7+9+11+13+15+17+19=100. It looks like he figured since 10 odd numbers can sum to 100 and since 50 is 1/2 of a hundred so maybe 5 odd numbers can sum to 50?

Welcome to the forum!

Just between you and me you might have what he wants. But look at this, supposedly a mensa quiz question answer for this problem.

Which is not quite correct, should read:

If you google for this you will find many other strange answers.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.