You are given a task of locating one faulty coin out of 99 identical in appearance coins i.e. 98 of equal weight and one of a lesser weight; and to achieve it within seven weighings, using a balance scale.
Sounds familiar and easy (37>99)?
Easy? Not quite!
How can you accomplish it if no coin may be weighed more than twice ?
Bonus task: After devising the requested procedure please generalize:
How many coins (n-1 normal and one lighter) can be resolved within k weighings?