The number of A is 78, which is twice the number of B. What is the sum of the two numbers of A and B?
甲数是78，是乙数的2倍，甲乙两数的和是多少．
<gadget id="calculator">78 / 2</gadget>
<output>39</output>

<gadget id="calculator">39 + 78</gadget>
<output>117</output>

<result>117</result>