The sum of the three numbers A, B, and C is 46. The number A is 4 more than the number B, and the number B is 3 more than the number C. What is the number B?
甲、乙、丙三个数的和是46，甲数比乙数多4，乙数比丙数多3，乙数是多少．
<gadget id="calculator">46 - 4</gadget>
<output>42</output>

<gadget id="calculator">3 + 42</gadget>
<output>45</output>

<gadget id="calculator">1 + 1 + 1</gadget>
<output>3</output>

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

<result>15</result>