The average of the three numbers A, B, and C is 150, the number of A is 48, and the number of C is twice that of B. What is the number of B?
甲、乙、丙三个数的平均数是150，甲数是48，丙是乙的2倍，乙数是多少．
<gadget id="calculator">150 * 3</gadget>
<output>450</output>

<gadget id="calculator">450 - 48</gadget>
<output>402</output>

<gadget id="calculator">402 / 3</gadget>
<output>134</output>

<result>134</result>