When Wang Hu subtracted 2.4 from a certain number, he mistook 2.4 as 4.2, and the calculated result was 38.8. What is the correct result of this question?
王虎计算某数减去2.4时，把2.4误看成了4.2，计算的结果是38.8，这道题正确的结果是多少？
<gadget id="calculator">38.8 + 4.2</gadget>
<output>43</output>

<gadget id="calculator">43 - 2.4</gadget>
<output>40.6</output>

<result>40.6</result>