Math Problems
of the Month
OSU-Marion
May 2005
Try your hand at these problems. Each month I will
post a few of my favorite math problems and puzzles. Some can be
solved by algebra, some need some clever intuition, some need a little
elbow grease. I hope you enjoy them as much as I do.
Submit answers to Dr. Maharry in MR 370 or at
maharry@math.ohio-state.edu.
I will post the names of those who submit correct
solutions outside my door and on my web site.
- When Kyle drives to work at an
average
speed of 48 miles per hour, he arrives 9 minutes late. When he drives
to work at an average speed of 64 miles per hour, he arrives 9 minutes
early. At what average speed should Kyle travel in order to arrive at
work exactly on time? (Are you sure?)
- When the expression (358)(447)
(559) is evaluated, the product ends with a string of zeros. How many zeros will be at the end of this
product?
- Take a
parallelogram as in the figure. Pick any point in the interior and draw lines
from that point to each of the four corners. Color opposite triangles red and
blue (as in the figure). Use some basic geometry to show that no matter where
the point is placed the total area of the two red triangles will equal the
total area of the two blue triangles.
- In this matchstick puzzle, move exactly 2 sticks to end up with
exactly 4 equal sized squares
- The Number Grid Puzzle:
In
the grid shown below place eight digits from 1 through 8 - one
digit per circle - in such a way that numbers that differ only by 1 (1
and 2, 2 and 3, 3 an 4, etc.) will not be placed in circles directly
connected by a straight line
