Mensa type logic

There is enough information in the picture to answer the question but you'd need a computer and a little bit of math programming to do it. ASSUMING the person asking the question is right about the distances, there should be one place only where circles around those three cities meet (which is where you are) and then you'd want to take the distance on a great circle arc from that point to Brazzaville.

These are only made up distances. It is purely a letter logic puzzle where you substitute letters for numbers to arrive at the sum , but cannot work out the logic

I don't picture any sort of letter logic solving this one; it's a geometry problem.

If ALGIERS was 318, you would have 61c + 24v + 2, but you don't. 233 is prime, so no multiplication. You can't use just the vowels since all five vowels are represented but you only have four equations. I don't see it.

It's not a geometry problem, it's geographically impossible.

Take a look at this previous question :

http://able2know.org/topic/163189-1

Is there a website where they list Mensa's tricks alphabetically (from '31' to '56')?

I get 464 miles, but it's easy to screw up the addition.

What was your logic for the solution?

Let a=1, b=2, etc.

Then add up all the letters...

Then tack on an additional 30 for each letter...

...to get the distance.

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EDIT:
For example CAIRO gives us 3 + 1 + 9 + 18 + 15 = 46,
Add 30 * (# of letters) to that to get 196.
This seems to work for all of them.

And...

...I apologise for the rather cryptic comment above, which was apparently too cryptic for anyone on earth to understand. I meant for it to serve as a sort of hint about how the logic of this signpost worked.

One way of making the four city names yield the appropriate distances is to assign 'a' a value of 31, 'b' a value of 32, and so on, until you end by assigning 'z' a value of 56. Then you can add up those values and get the appropriate distance to each city.

[C + A + I + R + O = 33 + 31 + 39 + 48 + 45 = 196]

So when I said above that "alphabetically" meant the same thing as "from '31' to '56'" I was trying to hint to people that the trick to solving this puzzle was to assign the letters 'a' through 'z' values from 31 to 56, respectively, and then to add them up.

Speaking cryptically seems to blow up in my face half the time, so I think from now on I'll leave cryptic remarks to the puzzle-masters at Mensa.

Once again, a very nice solution.