Revealed: how to become a top banana and solve the brain teaser of the GCHQ spy heads
- GCHQ said the fruit bowl puzzle should be colored with only four colors
- The test was intended to illustrate the four-color theorem developed in 1852
- GCHQ hopes the puzzle will inspire a new generation of codebreakers
According to GCHQ, the fruit bowl puzzle – completed below – had to be colored with only four colors so that the pear is green, the orange is orange, the apple red and the banana yellow.
The test is designed to illustrate the four-color theorem developed in 1852 by Francis Guthrie, who noted that it takes no more than four colors to complete a map, so no two adjacent regions have the same color.
It became the first major theorem to be proven with a computer.
It’s one of the puzzles in a new children’s book that the spy heads hope will inspire codebreakers of the future to join GCHQ.
The GCHQ fruit bowl puzzle was designed to illustrate the four-color theorem developed in 1852 by Francis Guthrie, who noted that it takes no more than four colors to complete a map, so no two adjacent regions are the same color