A hunting dog finds a running rabbit 35 meters away from it, and immediately chases after it. It is known that the rabbit runs 7 steps. , Ask: How far can the hound run at least to catch up with the rabbit?
一只猎狗发现离它35米远的前方有一只奔跑着的兔子，立刻紧追上去，已知兔跑7步的路程猎狗只跑4步，但猎狗跑3步的时间兔却能跑4步，问：猎狗至少跑出多远就能追上兔子？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 * (3/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">4 / 7 / (3/4)</gadget>
<output>16/21 = around 0.761905</output>

<gadget id="calculator">1 * (16/21)</gadget>
<output>16/21 = around 0.761905</output>

<gadget id="calculator">1 - (16/21)</gadget>
<output>5/21 = around 0.238095</output>

<gadget id="calculator">35 / (5/21)</gadget>
<output>147</output>

<gadget id="calculator">147 * 1</gadget>
<output>147</output>

<result>147</result>