There are 4 wrenches just unpacked from a box. They all look the same. There might be one defective item which is either heavier or lighter. Fortunately there is a fifth one that is standard. If you can use a scale to weigh only 2 times, can you find out:
- Is there a defective wrench?
- If there is a defective item, is it heavier or lighter?
You can weigh the whole lot of spanners and then weigh one. This doesn't neccessarily work but if you pick a normal one, you can divide the whoile mass by 5 and see if you come up with the weight of the single one you weighed!
Posted by Lozza
on 2004-09-13 04:06:32