(Not math) Father and son are in a car accident. They are both severely hurt and need medical attention. They are rushed to the hospital. When the son is on the operating table, the doctor comes in and says: "I can not operate on this boy, this boy is my son." Who is the doctor? (as allways..should be easy but so many miss it ;-)
offcource Please Register or Log in to view the hidden image! I have tried this one on a lot of my collegues and I think it is all the "boy" and "son" talk that throws them of. "grandfather" is a common answer hehe.. but It's also the fact that a lot of people think that the doctor automaticly is a man :-D
Still driving a car through the desert... I have an elegant solution of 45 barrels using equally spaced stations of 50 miles, never transferring over 10 gallons, and arriving with an empty tank. The algorithm is simple: Assume 1 station every 50 miles. On each trip into the desert, fill up your tank from each station you come to, until you reach an empty station. Drop off the spare drum at this point and turn around, filling up again from each station (you will always transfer 1/2 a tank). Repeat until you drop off a drum at the 300 mile mark. Repeat again until drop off a drum at the 200 mile mark. Repeat again until you drop off a drum at the 100 mile mark. Drive through the desert, reaching your goal with an empty tank! There's a nice binary pattern. It takes 1 trip to get a barrel to the first station, 2 trips to the second, 4 for the 3rd, etc. Each new station reached means consuming all fuel at previous stations. Placing the 300 mile drum costs 32 drums. Placing the 200 mile drum costs 8 drums. Placing the 100 mile barrel costs 2 drums. 42 drums, plus the three placed, gives 45. A little over the 42 solution, but neater and adheres strictly to the rules.
No no no....this car thing is easy. You stop by the convenience store 10 miles away and pick up a whole bunch of rope, maybe trade them some of your unlimited fuel or something, then you go back to your fuel dump, tie up a whole bunch of barrels and drag them through the desert.
How can you place a tank at 100 miles in 2 tanks, this is impossible. you have 1 full tank of fuel and carry another full tank. I tank gets you a hundred miles. Drop 1 tank off at 50 miles. 50 miles out, 50 miles back, 1 tank used, 1 dropped off Fill up your tank. Go to 50 miles. Use 1/2 a tank, fill up half with tank at 50 miles 1/2 tank left at 50 miles. With full tank go to 100 miles and drop off tank and go back to 50. I tank at 100 miles. Empty tank filled with half tank left at 50 to get you home. Thus in total you have used 3 tanks to drop off one tank at 100. Now you may think wow, 1 tank extra, big deal, but the number of tanks used to place tanks further away increases exponentially, and so it magnifies. Being totally within the rules I used this algorithm to show that you used something like 83 tanks. Nobody found less by working totally within the rules As I am usually right, I believe there is a mistake in your algorithm for finding 45 tanks working totally within the rules, so you better go back and check! This has used 4 tanks.Please Register or Log in to view the hidden image!
That indeed seems correct, however I'd say it would be more entertaining to harness the vultures circling around you. First, pretend to be dead...when they come down, take some of that convenience store rope, tie it around their necks (we know that the number of vultures in a desert is infinite. When you kill one, 5 more appear from nowhere. The laws of conservation don't hold for vultures), kill one, eat it for dinner. Repeat until you have captured enough to fly you and your jeep out of the desert.
This is a nice onePlease Register or Log in to view the hidden image! How does this work: http://mr-31238.mr.valuehost.co.uk/assets/Flash/psychic.swf
I like that one. Very clever presentation of maths magic Please Register or Log in to view the hidden image!
Pete: you discovered how it works? It's not that hard! Please Register or Log in to view the hidden image!
The number you get finally is always a multiple of 9. 9 and its multiples have the same symbol. that is the symbol is already decided and that of 9.
Time for a new riddle: In an alley two ladders are placed crosswise as in the image. The lengths of the ladders are respectively 2 and 3 meters. They cross at 1 meter above the ground. What is the width of the alley? Please Register or Log in to view the hidden image! edit: I renamed the thread, because it has nothing to do with car washing anymore Please Register or Log in to view the hidden image! edit 2: Ah, i can not seem to change the thread's title..:bugeye:
? Pim, 2.309 meters. (Excluding the affect of the thickness of the ladders). Knowing to believe only half of what you hear is a sign of intelligence. Knowing which half to believe will make you a genius
MacM: that's obviously not the right answer since one of the ladders is 2 meters long, so the width of the alley has to be smaller than 2. Indeed the thickness of the ladders can be neglected, should have said that, thanx Please Register or Log in to view the hidden image!
I agree Pim, I agree, I should have read closer. I looked at the 2m lable as segment and just did trig from there. Will have to go back an think on this one.Please Register or Log in to view the hidden image! Knowing to believe only half of what you hear is a sign of intelligence. Knowing which half to believe will make you a genius
