Monthly Archives: March 2017

Tangent Lines

Suppose to co-planar circles and have no points in common. Determine how many lines, if any, are tangent to both and ? Source: NCTM Mathematics Teacher, October 2006 Solution When one circle is inside the other, there are no tangent … Continue reading

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Wins and Losses

A person starting with makes eight bets and wins exactly four times. The wins and losses occur in random order. If each wager is for half the money she has at the time of the bet, how much money will … Continue reading

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Nested Square Roots 2

Find the value of Source: NCTM Mathematics Teacher, October 2006 Solution Let By substitution Squaring both sides Using the quadratic formula to solve for is an extraneous solution because the expression cannot be negative. Answer:

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Digital Clock

The display on a digital clock reads . What will the clock display twenty-seven digit changes later? Source: NCTM Mathematics Teacher, October 2006 Solution The figure shows there are four digit changes from to corresponding to four minute intervals. Thus, … Continue reading

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