Two creepers, one jasmine and the
other rose, are both climbing up and round a cylindrical tree trunk. The
jasmine twists clockwise and the rose anticlockwise, and they both start at the
same point on the ground. Before they reach the first branch on the tree the
jasmine has made 5 complete twists and the rose 3 twists. Not counting the
bottom and the top, how many times do they cross?
Answer:
Seven: The best way to find the solution to this problem is
to make a practical experiment.
Make a vertical cut in the tree
trunk and peel off the trunk to form a long rectangle. Across the rectangle
draw 5 parallel lines to represent the jasmine and another parallel line for
the rose. Then you will be able to see the seven crossing positions.
No comments:
Post a Comment