The figure on the left should be redrawn so that the circles are each big enough to hold a penny.
Take four pennies. The problem is to put a penny in each of the shaded circles. However, there's a catch. Here's the rules that you have to follow.
To begin, take a penny. Put your finger on a circle. There is an arrow that points from that circle to another circle, and that's where you have to put the first penny.
Continue in this way, each time putting your finger on an empty circle and placing a penny where the arrow points to.