Syvum Home Page

Home > Math Puzzles & Brain Teasers > Print Preview

Math Puzzles & Brain Teasers


The Creeper on the Tree

View Puzzle Solve Puzzle

Hide all answers   View all answers   Print   Try the Quiz

1. A creeper plant is climbing up and around a cylindrical tree trunk in a helical manner. The tree trunk has a height of 360 inches and a circumference of 48 inches.

If the creeper covers a vertical distance of 90 inches in one complete twist around the tree trunk, what is the total length of the creeper?
Answer: 408

Solution:

puzzle : creeper on the tree To make visualization easy, it is convenient to conceptually open out the bark of the tree trunk and flatten it. The cylindrical surface will then be a rectangle (as illustrated in the figure alongside for 4 twists of the creeper).

It may be noted that:
Width of the rectangle = Circumference of the cylinder = 48 inches.

Height of the rectangle = Vertical distance on the cylinder = 90 inches (in one twist).

Using the Pythagorean Theorem for a right-angled triangle,

Length of the hypotenuse = (482 + 902) 1/2 = 102 inches.

Now, the number of twists the creeper makes around the tree trunk is 4 (= 360 / 90).

If the length of the creeper (as given by the hypotenuse) is 102 inches in one twist, then the total length of the creeper in 4 twists is 408 inches.

Food for thought:

Is the total length of the creeper in the above calculation the actual length or the minimum length?


  Try the Quiz :     Puzzles & Brain Teasers : The Creeper on the Tree


Contact Info © 1999-2017 Syvum Technologies Inc. Privacy Policy Disclaimer and Copyright
Previous
-
Next
-