A grade A pencil costs 7 cents a piece; a grade B pencil costs 3 cents a piece. Zhang Ming can buy exactly how many two different pencils with six cents.
甲级铅笔7分钱一支；乙级铅笔3分钱一支．张明用六角钱恰好可以买两种不同的铅笔共多少支．
<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">10 / 10</gadget>
<output>1</output>

<gadget id="calculator">6 * 1</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>