A section of road has been built, 90 meters have been built, which is 30 meters less than the unrepaired three times, how many meters of this road are still unrepaired?
修一段公路，已修了90米，比未修的3倍少30米，这条公路还有多少米未修？
<gadget id="calculator">30 + 90</gadget>
<output>120</output>

<gadget id="calculator">120 / 3</gadget>
<output>40</output>

<result>40</result>