A spider has 8 legs, and a dragonfly has 6 legs. If spiders and dragonflies have 450 legs in total, and the number of spiders is three times that of dragonflies, how many spiders are there?
一只蜘蛛有8条腿，一只蜻蜓有6条腿，如果蜘蛛、蜻蜓共有腿450条，蜘蛛的只数是蜻蜓只数的3倍，那么蜘蛛有多少只．
<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<gadget id="calculator">6 + 24</gadget>
<output>30</output>

<gadget id="calculator">450 / 30</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>