There are 3 roads from A to B, and 4 roads from B to C. How many ways are there to go from A to C?
从甲地到乙地有3条路，从乙地到丙地有4条路，从甲地到丙地共有多少种走法．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<result>12</result>