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, 14:10:40 UTC 18 years ago
A and B are thus filling is at the rate of 5 gallons per hour.
A and C are filling it at 4 gallons per hour.
As B fills twice as fast a C, C must thus be filling at the rate of 1 gallon per hour.
Therefore C alone would take 20 hours to fill it.
Which is, I believe, the answer you first thought of.
Re: Easy, I think
October 24 2002, 14:33:51 UTC 18 years ago
The minute error must therefore have been in the Strongbow/Frijj exchange rate. I guess I overlooked the implied assumption that having lots of Strongbow is considered "good" for the purpose of this question.
Re: Easy, I think
October 24 2002, 16:02:08 UTC 18 years ago
If I have to explain it...
<audience-shouts>...it wasn't funny!</audience-shouts>
Re: Easy, I think
October 24 2002, 16:19:19 UTC 18 years ago
Re: Easy, I think
October 24 2002, 17:12:10 UTC 18 years ago