Replies

Yes but not explicity (if you know what I mean). The way NPV works is to take the given array of period end cashflows (20, -2, -2 in your case) and discount them to the start of the first time period. If you have yearly time periods, then providing 10% as the input is fine. If you have monthly time periods, then you will need to adjust the interest rate …

adjusted interest rate = (1 + annual rate) ^ (1/12) – 1

If you want the discounted value at the end of the time period, then multiply the answer by (1+interest rate).

In your example, NPV(10%, 20, -2, -2) gives 15.03. This is the same as 20 / 1.1 – 2 / 1.1^2 – 2 / 1.1^3 (20 discounted for 1 year, -2 discounted for 2 years, -2 discounted for 3 years. Note: you need to enter the signs of the cash flow correctly!

Correct! (on both counts).

Actually, I will have to ding you a little because, by your definition of prime, -7 would also qualify – see wikipedia. Or are you using ‘whole numbers’ to mean only positive? However, see wikipedia again

Looking good. I’m a bit unsure about why it jumps 2 squares when in turns a corner – guess it must be in the code somewhere – I will take a look. Also, it doesn’t seem to realize when it gets to the X.

Lastly, this will work in a closed maze but not an open maze (assuming that I have the terminology around the right way). A closed maze is where there is one really big loop and wall following will work. An open maze consists of two or more closed mazes where you need to cross over from one ‘arm’ to the other to solve.

more than you ever wanted to know about mazes – there are some downloadable stuff about half way down.

Good news – read up on my linksys router and some ‘how to’ web sites and I now have the laptop and the desktop seeing each other’s share files. I did have trouble getting the laptop to edit the desktop files – blocked for some reason – but the use of the word blocked gave me the clue. Once I had given a range of IP address the correct access level in zonealarm – it was smooth sailing.

The main trick is to make sure that the workgroup / domain names are the same – I keep on forgetting that.

There are two outstanding items – do I need to update my routers firmware – the how to I read on that looked scary.

The other outstanding question is how to I network to the ibook – now I have to read its manual.

Ok, I’ve searched and read. I think there is a bunch of stuff that I know nothing about. I’ve put together a list of things that I need to learn …

– how to share folders (I think I have that under control)
– view shared folders from another pc / mac on the network
– ping the other pc / mac
– ping the router
– view the setup page on the router (is that via the routers IP address?)
– find out all the IP addresses on the network

Any suggested reading?

Is the size of the graphic open to VBA?

Ahh – I want to anchor the right side of the graphic to the right side of a cell.

^ 2

Problem fixed – it turns out that some of the user defined functions actually make a call on a dll and there were problems with the dll – nothing to do with excel. No wonder I couldn’t reproduce the issue with a cut down version.

Is Hong Kong a country?

Correct – except that I know it as “what the old lady said after looking in her purse”

ouch

This kept my up last night! Do we have some code that converts a hides a table?

Ah – thanks for those probabilities …

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1) A in 1, B in 1 is 50% * 31/63 = 31/126 = 24.6%
2) A in 1, B in 2 is 50% * 32/63 = 32/126 = 25.4%
3) A in 2, B in 1 is 50% * 32/63 = 32/126 = 25.4%
4) A in 2, B in 2 is 50% * 31/63 = 31/126 = 24.6%

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[/indent]I’m going to stick with my comment … “The probability that A will meet B in round 1 under 1) and 4) above is zero. The probability that A will meet B in round 1 under 2) and 3) above is 1/32” but I probably should have added “give that you have already allocated A to a match.”

The way I typically look at these sorts of things is … There are two groups of 32 people. One person from the first group is placed in each of the 32 matches. So A is placed in match M. Now, the chance that B is also placed in match M – and hence meets A in round 1 – is 1/32.

So, the chance (overall) that A meets B in the first round is
= 31/126 * 0% + 32/126 * 1/32 + 32/126 * 1/32 + 31/126 * 0
= 0 + 1/126 + 1/126 + 0
= 2/126
= 1/63.

Which is a long way of saying that my answer is that post was WRONG because I had thought that the four outcomes all had a 25% probability and led me (incorrectly) to 1/64.

Steve – Sorry, but I don’t think that I was clear. The answer to the original question (as provided by Hans and you) is 1/32. The post that I quoted was trying to answer the probability that they meet in the first round. Hans (and you) were saying 1/63 which sounds very reasonable to me.

In post 523,791 – I was trying to come at the answer by a different route – I divided the contestants into two groups BEFORE the matches – if you think of the matches being held on 32 courts, the the each member in G1 would just go to any old court (it makes no difference). Then each player in G2 is randomly assigned to a court where they meet their opponent. Now, if each outcome (1, 2, 3 or 4 from post 523,791) has an equal probability, then the chance of A meeting B is 1/64. As I said, I don’t think that my assumption that each outcome has an equal probability of 25% is correct. How did you work out the prob for outcomes 1 to 4?

A christmas decoration and to answer your other question australia, twice over the World IX