numerical challenge

I saw this posed as an interview question:

(usual exponent notation) What are the last 3 digits of 171 ^ 172?

Presumably, one is given pen and paper.

Is there a trick here? The second digit isn't too tough, but the third is a lot of work.

That'll be why you didn't answer it.

Perhaps not even then. All the offered solutions require knowledge of congruences, which is part of basic number theory. Unless a person has done a maths degree, or happens to have encountered it in passing (my situation), they're unlikely to be sure that the required steps are mathematically valid.

I can't imagine number theory having much application either to electronics or stock-broking.

Its most obvious use, outside pure-maths, is in cryptography, but if you're interviewing someone for such a role, there are likely to be much better questions.

Sylvia.

wtf!!!

Can't you do that in your head?

Jamie

Well, perhaps: (dropping all multiples of 1000 as in your other posts)

( 900 - 9^3 )^172 = ( 100 + (10-1)^3 )^172 = (10 - 1)^516 + 100 * 172 * (10 - 1)^513 = (1 - 160) + 200 * (-1 + 130) = 1 - 160 - 200 = 641

This is easy on the calculations, but not just a single line....

Regards, Mike.

Good Lord. You can't read either. You're as bad as Bloggs.

Typical Fields. Stupid as a stump.

One that simple is. ...at least for someone who thinks they can design.

Did you expect otherwise?

I've seen job interview tests for stock brokers. About 1/3 of such a test consists of 'numerical challenges' like the one above. From every

Well, that's closer than I got. Damnation, I should have spotted that

The cited page suggests to me that the one line solution will not involve the binomial theorem.

Sylvia.

There's no point conversing with Fields or Bloggs. They are both a lot more crabby than they are sensible.

Neither is an engineer, either.

Late at night, by candle light, John Fields penned this immortal opus:

Larkin showed one of the _incorrect_ answers. Maybe not very clear to all, but most of us seem to have understood it.

Your need to have everything spelled out in excruciating detail is symptomatic of some kind of comprehension deficiency. There are meds for that, speak to a doctor.

- YD.

No, he's just a prissy old hen. There are no drugs for that.

I actually thought Bloggs was, until the Solyndra thing. Truly amazing.

You call that crap circuit test engineering? It barely tests more than ability to read schematic symbols.

to read schematic symbols.

It's a good, quick way to disqualify over half of the engineering and technician applicants.

During the dot.com bubble, I worked for a software company that would (by way of analogy) have employed the person on the grounds that they at least knew which was the base. Apparently, the management thought that any 'programmer' was better than no programmer.

Sylvia.

ability to read schematic symbols.

Where are these applicants coming from? The Republicans in Engineering Club?

I am reminded of another "puzzle": how many terminal zeros are there in 4089! (4089 factorial)? Solve it in less that (say) ten minutes. No electronic or mechanical calculator allowed.