There are three kinds of ribbons: red, yellow, and green. The red ribbon is (3/15) meters longer than the yellow ribbon, and the green ribbon is (1/15) meter shorter than the yellow ribbon. How many meters is the difference between the red ribbon and the green ribbon?
有红、黄、绿3种彩带，红彩带比黄彩带长(3/15)米，绿彩带比黄彩带短(1/15)米．红彩带与绿彩带相差多少米？
<gadget id="calculator">3 / 15</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/5) + (1/15)</gadget>
<output>4/15 = around 0.266667</output>

<result>4/15 = around 0.266667</result>