Stage: 4 Challenge Level: 
A blue coin rolls round two yellow coins which touch. The
coins are the same size.
How many revolutions does the blue coin make when it rolls all the way round the yellow coins?
Investigate for a line of 'n' coins
Visualising. Inequality/inequalities. Circles. Loci. Stage 5 - Reviewed 2012. Number theory. Manipulating algebraic expressions/formulae. Mathematical reasoning & proof. Patterned numbers. Arcs, sectors and segments.
Published December 1997.
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