Recent content by X=7

Oh, the irony!:eek: Another numeric computation one that hasn't been mentioned is the über-cruncher program IDL!

Thanks ktoz - I get it now. Heh, I'm not a programmer & got my maths degree more than 20 years ago so rather rusty! AlephZero's rearrangement shows the condition for the difference to be prime is that n or 2n-1 would have to be prime. Having a look at the first "easier" case, n prime, would...

Hi ktoz & yes nice one-liner, AlephZero. Well, with n-k=1, the expression just reduces to n, so the condition is that n itself must be prime. Similarly for n-k=2, 2n-1 must be prime. ktoz, well spotted! I agree it's an interesting pattern, but I don't know enough to know if you're on to...

Hi HallsofIvy. I think you've misread courtrigrad's post. It (correctly) says that the sum to 100 has last two digits 13. Best wishes X = 7

Yes, lunarmansion, JasonRox is surely mistaken on that one. I too have studied Classics & Maths and, Jason, absolutely cannot agree. You are well wrong on that one! Best wishes x=7

Hi - I didn't see the original (removed) link, but suggest you check out a famous book called Figuring by Shakuntala Devi. All the above methods are just basic examples of the Vedic system she resuscitated. Older members may remember she's the prodigy whose mental arithmetic beat the...

Hello Jacinda! Don't be downhearted; what you've done by mailing the candidates at home is in effect a cold mailshot. Think about it, what do most people do with unsolicited approaches when we all get letters at home advertising things we might be interested in? Bin them! [Edit:Just saw...

That is what my instinct is telling me, but happy to be proved wrong:-p. Thanks for the friendly introduction, will do!:smile: X=7

Thanks for the fast replies, Danger and NoTime:smile:. Danger, yes, I reckon you're about right but I probably won't have time to try the ice thing; I came on this physics forum in case these are well-known results. Ditto to NoTime, I'd worked that one out for myself:biggrin:! Thanks anyway...

Hello everyone, new member here:smile:. My sister asked me this today - real-life physics at work! She's making Christmas pud & the instructions say it takes 8 hours to cook. However, her bowls are too small, so she's made two little ones instead, and she asked how long to allow to cook...