4 parts of 40

BelieveNothing · 10-24-2009, 07:39 AM

Which 4 numbers that add up to 40 altogether can be used together with + or - symbols to make any whole number between 1 and 40 when each number may only be used a maximum of once?

Steve · 11-10-2009, 04:37 PM

Anyone got an idea for this puzzle? I've tried a number of combinations but drew a blank and would really like to know the answer.

edna · 11-10-2009, 08:05 PM

I will not even attempt it lol

butterflysecrets · 11-12-2009, 03:29 AM

numbers are not my forte, but i'm wondering if you start with a negative number then add positives??

Steve · 11-12-2009, 08:10 PM

BelieveNothing was kind enough to PM me the answer and it turns out it's simpler than I thought. I was over complicating the puzzle as I thought you had to use all 4 numbers each time to get a total of 1 - 40. But that is not the case, the solution uses 1, 2, 3 or all 4 of the numbers to get the combinations 1 - 40.

So for example, if one of the four numbers was say 1 then you use that on it's own to get the number 1 and don't need to involve the other 3 numbers. Make sense?

So knowing this information has anyone here got the brains to work this out? There are no negative numbers bfs.

butterflysecrets · 11-13-2009, 03:09 AM

nope, do not have the brains for this...

Steve · 11-16-2009, 06:50 PM

Nobody want a go?

I'm sure Believenothing won't mind me dropping a clue, so I'll reveal the first digit is 1 and the remaining numbers are all odd.

Steve · 11-17-2009, 10:44 PM

Think you guys are out of practice with number puzzles, I'm going to have to post some up to get your brains thinking again.

Meantime, I'll reveal the answer for this one as it doesn't look like anyone is going to solve it. The numbers are:

1, 3, 9 and 27

Nice puzzle BN, thanks for posting. It sure got me thinking.