kangaroo
Source: Netherlands 1995
June 28, 2009
analytic geometrycombinatorics unsolvedcombinatorics
Problem Statement
A kangaroo jumps from lattice poin to lattice point in the coordinate plane. It can make only two kinds of jumps: to right and up, and to the left and down.
The start position of the kangaroo is . Show that it can jump to the point and determine the number of jumps needed.
Show that if the start position is , then it cannot reach .
If the start position is , find all points with which the kangaroo can reach.