A teeter puzzle
Puzzle
If all of those little boys were seated
on one arm of the see saw, how many
girls would it require on the other
end to keep the balance even?
Comment
Solve the puzzle as if a child's distance from the center does not matter.
Solution
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A teeter tater illustration gives a
clearer idea of the algebraic meaning
of the two sides of an equation than
could be acquired from months of
hard study. Let us illustrate the first
principle of algebra which tells us
that like quantities added or
subtracted from both sides of the
balance do not change the equilibrium.
We will solve the puzzle by the
principle of cancellation. There are five
boys on one arm of the balance and
three on the other, so we cancel off
three from each end. Then as there
are three girls on one end and six on
the other, we will cancel off three
from both sides so as to leave two
boys balancing with three girls.
Startling as it may look, we find that
two of those little boys weigh the
same as three girls.
Answer
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The eight little boys were placed on one arm of the see-saw require twelve of the fat girls to balance them. You see; to make the picture deceptive the little boys were filled with lead.
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