Xiaoxuan and grandpa walked along the lake. They set off from a certain place by the lake at the same time and walked in the same direction. If they all walk slowly, Xiaoxuan can catch up with grandpa by walking 3 laps. If they all walk fast, Xiaoxuan can catch up with grandpa by walking 6 laps. It is known that the speed of both of them walking fast is 9 more per minute than walking slowly. Meters, so how many meters per minute is Xiaoxuan's brisk walking speed?
小轩和爷爷两人沿着湖边散步，他们从湖边某地同时出发，同向而行．如果他们都慢走，小轩走3圈就可以追上爷爷，如果他们都快走，小轩走6圈就可以追上爷爷，已知他们两人快走的速度都比慢走每分钟多行9米，那么小轩快走的速度是每分钟多少米？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">9 * (5/6)</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">9 - (15/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(5/6) - (2/3)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(3/2) / (1/6)</gadget>
<output>9</output>

<gadget id="calculator">9 + 9</gadget>
<output>18</output>

<result>18</result>