A supermarket bought a batch of socks of the same style at 5.4 yuan per pair, and then sold them at 7.5 yuan per pair. When these socks were sold to only 10 pairs, they had already made a profit of 336 yuan. How many pairs of socks does this supermarket buy?
某超市以每双5.4元购进一批款式相同的袜子，然后以每双7.5元售出，当这些袜子卖到只剩下10双时，就已获利336元．这个超市购进多少双袜子？
<gadget id="calculator">7.5 - 5.4</gadget>
<output>2.1</output>

<gadget id="calculator">336 / 2.1</gadget>
<output>160</output>

<gadget id="calculator">160 + 10</gadget>
<output>170</output>

<result>170</result>