MATHEMATICS ENCYCLOPEDIA

A woman was travelling with her young son, a carton of cakes and a wolf She had to cross a river in a small boat large enough for herself and one of the three . The following problems arises: If she left her son alone with the cakes, he could eat them.  If she left the wolf alone with the boy, the wolf would eat him. The question is how could she make the crossing ? Puzzled! See the solution below. Solution: The woman takes the boy across, returns alone. She takes the carton of cakes across, returns with a boy. She takes wolf across, return alone. Then she takes the boy across.

In A.D. 1120, the king of England decreed that in his country, the yard will be used as the unit of length. It was the distance from the tip of the king's nose to the end of his outstretched arm. The original standard adopted by France was called a foot . It was equal to the royal foot of the king. In 1799, the kings foot was replaced by "meter". Then it was defined as one ten millionth distance from the equator to the north pole along a longitudinal line that passes through Paris . In 1889, 1 meter was defined as the distance between two lines on a specific platinum-iridium bar stored under controlled conditions. In 1960, meter was redefined as 1,650,763.73 wavelengths of a particular orange-red light emitted by atoms of Krypton-86 in a gas discharge tube . 1 meter = 100 cm The meter was redefined again in 1983, this time as the distance which light travel in a vacuum in 1/299,792,458 seconds. This remains the current definition. Note that in all these re...