If A and B can fill a tank in 4 hours, A and C can fill the tank in 5 hours, and B fills twice as fast as C, how long does it take for C to fill the tank alone?
Fairly straightforward, but either the Invariants being slow, or we were all being polite and letting other people have a chance to figure it out...
So, I'm broswing around Sainsbury's, when I see they have large packs of Strongbow (18x440ml cans, normaly £14.99) reduced to half price. Seems like a good offer, but they also have 4-packs at £3.59 each with 500 nectar points if you buy two packs. In addition, these cans have x% extra free, making them a full pint. Question is, which of these offers is better value for money?
Re: Easy, I think
October 24 2002, 13:27:55 UTC 18 years ago
Cider: you can buy 72 440ml tinnies for GBP 29.96 with the first offer, or 72 pint tinnies accompanied by 4500 nectar points for GBP 64.62. We can multiply the 29.96 by 568/440 to get an equivalent volume of cider, so the effective cost of 72 pints of cider with the first offer is GBP 38.67. Therefore you need to find something worth GBP 25.95 to do with your 4500 nectar points in order for the second offer to be better. If you convert nectar points directly into shopping then they're only worth GBP 22.50, which makes the half-price offer slightly better. However, if you can find something more imaginitive to do with 4500 nectar points, then the offer with points becomes better. (Incidentally, you only need to purchase 152 pints of cider, or nineteen gallons of the stuff, to get enough points to go on a scuba-diving course for two. Glug glug!)
Incidentally, this analysis doesn't take into account the normal nectar points you earn from the two purchases, but I doubt they would make much difference.
Re: Easy, I think
October 24 2002, 14:26:42 UTC 18 years ago
Of course, another angle of attack is to ignore the extra free on the grounds that is the number of drinks that counts plus you get the bonus of slightly reduced hangovers. In this case you need to get over £5 per voucher, which is pushing your luck some.
The real danger with this sort of scheme is that you count your money twice, eg:
1) I've earned 500 points which is like saving £2.50!
2) I've used a 500 point voucher to save me another £2.50!
Re: Easy, I think
October 24 2002, 17:13:39 UTC 18 years ago
This is your private health insurance company speaking. Your premiums have just nontupled.